Explore published research on youth, including study methods and limitations.
Among 1,689 Egyptian men, cannabis users showed cognitive deficits compared to non-users, but the gap was smallest among illiterate, rural, and older participants.
California designed a four-protocol statewide program to study THC dosing for cancer nausea across ages, involving over 200 investigators and including children and elderly patients.
A major 1986 pharmacological review found cannabis's greatest health concern was its impact on youth development, while finding no proven brain damage and limited physical dependence in adults.
Animal studies showed chronic THC altered the hippocampus in rats, but required at least 3 months of exposure in young animals. Monkey studies did not consistently replicate these findings.
Among New York young adults, early alcohol use (ages 13-16) was the strongest predictor of later marijuana and cigarette use, supporting an age-dependent gateway pattern.
Delta-8-THC completely prevented vomiting in eight children aged 3-13 across 480 cancer chemotherapy treatments over up to eight months, with negligible side effects.
Among vocational high school students, 65% were heavy smokers by age 13, with strong associations with alcohol and marijuana use, poor grades, and multiple failed quit attempts.
Cannabis use before age 15 was associated with 2.7-30.8 times higher odds of mental health and behavioral problems, but most of this risk was explained by pre-existing family disadvantage and early adjustment difficulties.
In 131 children followed from birth, prenatal cigarette exposure was linked to lower reading and language scores in a dose-dependent pattern, while prenatal marijuana exposure showed no significant effect.
Among 99 cannabis users, only those who started before age 16 showed lasting visual scanning deficits. Age of onset was the sole predictor, not total amount used or current intoxication.
Prenatal cigarette exposure reduced birth weight but children caught up quickly. Prenatal marijuana showed no effects at birth but was linked to smaller head circumference by early adolescence.
31% of 566 adolescent marijuana users at alternative high schools quit within one year. Peer disapproval of drugs and negative personal attitudes about use predicted quitting.
Among 842 high-risk students, 70% used marijuana, over half had tried to quit and failed, and most viewed cessation programs as ineffective despite high interest in quitting.
Econometric study using cigarette prices as a natural experiment found evidence that smoking leads to cannabis use, but weak evidence that cannabis use leads to harder drugs, challenging gateway theory.
A 21-year study of 1,265 New Zealand children found cannabis use linked to crime, depression, suicidal behavior, and other drug use, with younger users (14-15) affected more than older users (20-21).
Brain wave study showing chronic cannabis users processed auditory attention differently, with reduced P3 responses to targets and greater effects in early-onset users, undetected by standard tests.
Review proposing cannabis may be a gateway to tobacco rather than the reverse, with university student research suggesting cigarette initiation often followed marijuana use.
Qualitative study finding Scottish teenagers' cannabis and tobacco smoking were "inextricably linked," with cannabis use serving as a gateway to cigarettes and a barrier to quitting tobacco.
Twin study finding cannabis dependence linked to 2.5-2.9x higher suicide risk even after controlling for shared genetics, while the depression link was explained by shared genetic vulnerability.
Adolescent but not adult cannabinoid exposure in rats produced lasting cross-tolerance to morphine, cocaine, and amphetamine in dopamine reward neurons, suggesting unique adolescent brain vulnerability.
fMRI study showing young adults prenatally exposed to marijuana had increased brain activation during impulse control tasks and more errors, with effects persisting after controlling for current drug use.
5-year follow-up finding 42% of teen marijuana users quit, with heavier use, male gender, being unmarried, and friends' use predicting continued consumption.
Study of 357 first-episode psychosis patients found 44% met criteria for substance abuse/dependence, primarily involving cannabis and alcohol, with higher rates in younger males.
Population-based study of 133 schizophrenia patients found male cannabis users developed their first psychotic episode 6.9 years earlier than male non-users.
Comprehensive review found strong evidence linking cannabis to psychosis, supported the existence of cannabis withdrawal syndrome, and called for more rigorous research on prevention and treatment.
Study of adolescent cannabis treatment seekers found nearly two-thirds experienced four or more withdrawal symptoms, though rates were lower than in adult studies.
UK study of 152 first-episode schizophrenia patients found 68% had lifetime drug use, with cannabis independently predicting earlier psychosis onset after adjusting for other substance use.
Three-year follow-up in Aboriginal communities found cannabis use decreased overall, but persistent users had higher rates of hallucinations, suicidal thoughts, and imprisonment.
fMRI study of 18-22 year olds from a 20-year longitudinal study found altered brain activation during memory tasks in those prenatally exposed to marijuana, despite normal task performance.
Early-life cannabis exposure was linked to subtle cognitive and psychiatric outcomes, with animal studies offering mechanistic clues but not human behavior.
Review of nicotine-cannabis interactions found co-use may enhance reinforcing and anxiolytic effects while having opposite effects on appetite and cognition, with adolescent co-use being a major concern.
Large twin study found common genetic factors drive adolescent problem use across tobacco, alcohol, and marijuana, while shared environmental factors drive experimentation but not progression to problems.
Study of 119 heavy cannabis users found high rates of depression (46%) and suicidality (42%), predicted by parental alcoholism and childhood adversity rather than cannabis or other drug use.
Teen cannabis+tobacco users showed verbal memory deficits and disrupted brain connectivity that only appeared during nicotine withdrawal, suggesting cannabis may damage memory circuits that nicotine temporarily masks.
Survey of nearly 2,000 Zambian students found 31% reported suicidal thoughts and 36% had used marijuana, with a modest but significant association between the two.
Twin study of 1,088 pairs found that childhood conduct problems contributed a small but significant genetic risk to marijuana use 8 years later, suggesting shared genetic vulnerability.
Brain imaging of 11 heavy marijuana users who started in adolescence found structural white matter damage in the corpus callosum connecting the prefrontal cortices.
13-year Norwegian study found frequent cannabis use linked to nearly triple the suicide attempt risk but not to depression, suggesting distinct pathways to suicidal behavior.
Review assembled evidence that the endocannabinoid system's major changes during puberty make adolescent brains especially vulnerable to lasting harm from cannabis exposure.
Pubertal rats given cannabinoids for 25 days showed persistent memory and social deficits lasting at least 15 days after stopping, while adult rats showed milder, more reversible effects.
Among 3,427 young women, those who used cannabis and tobacco simultaneously had 1.6x higher cannabis abuse risk, driven by environment (31%) rather than genetics (0%).
Among 1,779 adolescents in substance abuse treatment, those who continued or started smoking cigarettes had significantly higher odds of relapsing on marijuana and alcohol at 12 months.
In 284 population-sampled young adults, moderate cannabis and ecstasy use was associated with dose-related episodic memory decrements and increased attention lapses, though effect sizes were small.
Heavy teen marijuana use was linked to modest cognitive disadvantages, subtle brain differences, and poorer sleep. Some changes persisted past a month and sometimes resolved by three months of abstinence.
In 50,087 Swedish men followed for 33 years, the apparent link between cannabis use and suicide (OR 1.62) was fully explained by pre-existing psychological and behavioral problems (adjusted OR 0.88).
Young adults with adolescent cannabis use showed worse executive attention performance and stronger right prefrontal brain activation, suggesting less efficient attentional processing.
Cannabis users who started before age 16 showed increased brain activation during working memory tasks compared to later-onset users, independent of total use, suggesting less efficient cortical processing.
A WHO study across 17 countries found the gateway drug sequence varies with drug availability and cultural factors, suggesting common causes rather than cannabis itself driving progression to harder drugs.
Adolescent cannabis users showed memory recovery after 2-3 weeks of abstinence but attention accuracy remained impaired, suggesting different recovery timelines for different cognitive functions.
Among 4,075 young French adults, depression (OR ~8) and psychosocial factors predicted suicidal ideation, while cannabis use was not an independent predictor after adjustment.
Brief review linking cannabis use in adolescents to psychosis, depression, panic attacks, and suicidal thoughts.
Among 130 teens, heavy drinking predicted worse verbal memory, but only in those who did not also use marijuana.
First documented cases of cannabinoid hyperemesis syndrome (severe cyclic vomiting) in two teenagers with chronic marijuana use.
In 169 first-episode psychosis patients, cannabis use was linked to earlier onset and appeared to override the COMT gene's protective delay effect.
Review of brain imaging studies found white matter abnormalities in early schizophrenia, with adolescent cannabis use having specific effects on these measures.
Comprehensive review found recreational cannabis adverse effects were generally minor, with overall harms appearing less serious than alcohol, though vulnerable individuals faced greater risks.
Survey of 1,432 Seychelles adolescents linked cannabis, alcohol, and tobacco use to suicidal ideation, truancy, and poor parental monitoring.
Heavy cannabis-using adolescents had smaller hippocampi than controls even after 6.7 months of abstinence, with volume correlated to amount of prior use.
Pre-illness cannabis use in 109 first-episode patients was linked to better early social skills but worse academics, and daily use predicted acute (rather than gradual) psychosis onset.
In 7,753 Dutch twins/siblings, cannabis initiation heritability was 40% at age 16.5, with environmental influences growing with age, especially factors shared between twins.
In Finnish teens, general anxiety predicted later substance use (via depression), while social phobia appeared to protect against persistent alcohol use.
First documented case of marijuana-induced mania in an adolescent with no prior psychiatric history.
Among 109 first-episode psychosis patients, 57.8% had been previously incarcerated, with earlier cannabis use linked to incarceration history.
Late-adolescent cannabinoid exposure in rats produced recoverable general cognitive deficits but persistent spatial memory impairment lasting at least 75 days.
Critical examination of the gateway drug theory, arguing that common research designs cannot adequately control for confounding factors that explain the association.
Brain imaging found adolescent methamphetamine and cannabis users had enlarged striatal regions and higher novelty-seeking, with meth exposure correlating to both.
Review finding combination therapies (motivational + cognitive-behavioral + incentives) most effective for cannabis dependence, though long-term abstinence remains below 20%.
Preliminary study found a serotonin receptor gene variant influenced brain activation patterns after cannabis treatment in adolescents.
Adolescent but not adult cannabinoid exposure in mice produced lasting schizophrenia-like deficits, linked to reduced hippocampal mGluR5 and altered endocannabinoid metabolism.
Female adolescent rats showed greater locomotor depression and anxiety during THC withdrawal compared to males across multiple doses.
In adolescents with new-onset bipolar disorder, cigarette smoking predicted development of cannabis and alcohol disorders, while quitting smoking did not worsen mood.
Teen marijuana users showed reduced brain blood flow in multiple regions, but all differences disappeared after 4 weeks of confirmed abstinence.
Cannabis-using first-episode schizophrenia patients had earlier psychosis onset but better cognition, with 75% quitting cannabis spontaneously over follow-up.
Large Australian twin study found 72-80% heritability for cannabis use, early onset, and abuse/dependence, among the highest for any substance.
French study of 29,393 teens found daily cannabis users were 124 times more likely to try other illicit drugs, modeled through a stage-based progression.
The most famous and debated cannabis study: 1,037 New Zealanders followed from birth showed up to 8 IQ points of decline with persistent adolescent-onset use — but subsequent twin studies and meta-analyses suggest the true effect is smaller and partly confounded.
In 1,943 Australian adolescents followed to age 29, cannabis use independently predicted self-harm (2.4x risk), with most self-harm resolving spontaneously.
Young people seeking treatment for cannabis dependence typically had multiple psychiatric diagnoses, especially anxiety disorders like PTSD and social phobia.
The endocannabinoid system is active in embryos before brain development begins, suggesting early pregnancy cannabis exposure could disrupt fundamental developmental processes.
Largest early CH series: frequent long-term use common, abdominal pain prevalent, 91 percent of those who tried hot bathing reported relief. Follow-up was scarce.
Early cannabis use was linked to a 2.9-fold increased risk of suicide attempt in French students, with different substance-suicide patterns across France and the US.
Longitudinal study found the order of trying drugs did not predict cannabis use disorder; peer influence was the key factor.
Adolescent THC exposure in rats altered gene regulation through epigenetic changes in the reward system, directly increasing vulnerability to heroin self-administration.
THC selectively impaired spatial but not object working memory in adolescent monkeys, suggesting less mature brain functions are more vulnerable.
Twin study found shared genetic risk for nicotine, alcohol, and marijuana peaked at ages 14-17 and declined into adulthood as substance use became more environmentally driven.
Four-year study of 1,145 college students found cannabis use predicted late enrollment gaps while depression predicted early ones.
Study of 984 college students found "study drug" use was linked to escalating cannabis and alcohol problems and declining academic performance, not academic ambition.
Review found medical cannabis has the best evidence for pain and spasticity, with dizziness as the most common side effect and adolescent psychosis risk as the main safety concern.
The pesticide chlorpyrifos persistently elevated brain endocannabinoid levels in developing rats, even at the lowest dose tested, through enzyme inhibition.
Review found adolescent cannabis use predicts anxiety, depression, and psychosis more strongly than adult use, with earlier initiation increasing risk.
Females often show stronger cannabinoid effects. Estradiol is a leading explanation in animals, while human evidence remains mixed.
Abstinent adolescents with past cannabis use disorder showed abnormal brain patterns during risk-taking and reward processing that persisted after treatment.
Eight-year study of 67,000 Nevada teens found marijuana use had a larger negative impact on dental health than tobacco, increasing cavity prevalence and severity.
Children of substance-using parents showed reduced error-processing brain activity even before any cannabis use, suggesting an inherited vulnerability marker.
Adolescent cannabis users showed increased self-reflection brain activity when hearing their own motivational statements, and this predicted less use one month later.
Ontario surveys found 15.5% of students and 5.9% of adults reported prescription opioid misuse, with cannabis use predicting misuse in male adults.
In 1,103 French youth followed 18 years, childhood attention problems predicted adult tobacco and cocaine use, while early cannabis exposure predicted all substance outcomes.
Among 80 adolescents with bipolar disorder and cannabis use, 49% were heavy tobacco smokers and 70% were nicotine dependent, with smoking marking greater severity.
Male mice with BDNF deficiency became hypersensitive to cannabinoid effects on sensory gating after chronic young-adult cannabinoid exposure, with increased CB1 receptors in nucleus accumbens.
Systematic review of 9 trials found mostly inconclusive evidence for ER-based brief interventions reducing youth substance use, with some promising MI findings.
Multilevel analysis of 1,601 Croatian students found medium school and area SES associated with higher cannabis use, while low SES was protective.
In 1,803 children followed 15 years, oppositional behavior was the strongest predictor of cannabis and cocaine dependence, while the ADHD link was largely explained by opposition.
Parent survey found 84% of children with treatment-resistant epilepsy had reduced seizures with CBD-enriched cannabis, after trying an average of 12 medications.
53% of young adult tobacco users also used marijuana, and co-users had 25% lower odds of planning to permanently quit tobacco.
Two-year study of 976 high school students found heavy cannabis use alone predicted depression but not suicidality, while other illicit drug use predicted all three.
NAC helped adolescents achieve more marijuana abstinence without reducing craving more than placebo, suggesting it works through non-craving mechanisms.
In young adults, a childhood ADHD diagnosis was linked to executive function deficits, but regular adult cannabis use added no measurable cognitive impairment beyond ADHD alone.
In a study of 10,324 teens, cannabis use was linked to mental health problems, but the association was largely explained by co-occurring risk factors like truancy, alcohol, and adverse life events.
A 30-year longitudinal study found that intensive cannabis use was associated with increased suicidal ideation in males, with no evidence that suicidal thoughts drove cannabis use.
Chronic cannabinoid exposure in adolescent rats caused lasting spatial memory deficits linked to reduced hippocampal neurogenesis, while adult rats were unaffected.
Social network analysis of college students found marijuana and alcohol use clustered within friend groups, while exercise did not, suggesting substance use is more socially contagious.
Adolescent cannabis users showed poorer impulse control and abnormal brain connectivity between parietal and cerebellar regions, a pattern that correlated with recent use.
In 376 college students, inattention symptoms were independently linked to worse cannabis outcomes and strengthened the connection between use level and cannabis-related problems.
Longitudinal study of inner-city youth found increasing marijuana use trajectories were associated with over 3x the odds of weapon-related violence compared to no/low use.
Adolescent smokers who frequently used marijuana were 44% less likely to have attempted quitting cigarettes, with boys showing a stronger effect than girls.
Low-dose pesticide exposure increased brain anandamide levels in developing rats at doses below the traditional toxicity threshold, implicating the endocannabinoid system as a sensitive target.
Among 972 high school students, cannabis use was not independently linked to suicidal ideation after controlling for borderline and psychopathic personality traits.
Three adolescents referred for eating disorders actually had cannabis withdrawal syndrome, demonstrating how CWS symptoms can mimic disordered eating.
Cannabis use disorder worsened executive attention in adolescents with schizophrenia but not in healthy teens, with deficits linked to reduced anterior cingulate cortex surface area.
The Unplugged program reduced youth substance use across 7 European countries by modifying attitudes and norms, though the mediating effects were generally weak.
Critical review of seven evaluations found little evidence that the widely used Project TND school prevention program effectively reduces cigarette, alcohol, or marijuana use.
About 9-10% of participants in a U.S./Mexico border community had tried synthetic cannabinoids or Salvia, with current marijuana use being the strongest predictor.
Swedish monitoring detected over 50 different new psychoactive substances in emergency patients, predominantly young males, with synthetic cannabinoids among many diverse classes.
Among 9,288 Ontario students, about 1 in 5 had a history of brain injury, which was linked to cannabis use, mental health problems, and risky behaviors with sex-specific patterns.
Review found cannabis crosses the placenta and enters breast milk, with evidence suggesting adverse effects on fetal brain development that may persist into adulthood.
Among Arkansas high schoolers, cannabis (33% ever use), inhalants (19%), and prescription drugs (13%) were all linked to suicidality, with prescription drug abuse showing the strongest association.
The 2013 national youth survey found 23% past-month marijuana use among high schoolers, a rate that had not changed over time despite declining cigarette use.
Among 25,456 high schoolers, marijuana use was associated with twice the odds of gambling and gambling problems, alongside alcohol and prescription drug misuse.
Across 22 longitudinal cohorts, cannabis use was linked to about 29 percent higher odds of later depression, with exposure measures often weak and overall bias rated medium.
Daily cannabis users were more likely to meet hyperactive‑impulsive ADHD symptom criteria; nondaily users showed no subtype split.
Charlotte Figi: 50 seizures/day to 2-3/month on CBD cannabis extract. Single case that launched a movement, a drug approval, and a national policy shift.
A large Dutch randomized trial of the Healthy School and Drugs prevention program found no significant effects on adolescent alcohol, tobacco, or marijuana use at 32 months.
Among 290 adolescents with eating disorders, nearly half of those with bulimia nervosa reported substance use, with older age being the strongest predictor of regular use.
Longitudinal study found marijuana use predicted dating aggression in girls, hard drug use predicted it in boys, and alcohol predicted aggression timing for both sexes across grades 8-12.
RCT of 764 students found the Climate Schools online prevention program reduced truancy, psychological distress, and moral disengagement for up to 12 months.
Pilot of the Australian Climate Schools online drug prevention program in 2 UK schools found 85% of students found it easy to understand and 82% of teachers would use it again.
Canadian study found teens with ADHD reported cannabis use at 14.2%, comparable to or lower than the 16.5-26.0% rates in two general population samples.
Among 972 young adults using both cigarettes and marijuana, use patterns were correlated but quit motivation diverged: more desire to quit cigarettes but less confidence in success.
Study of 11,667 middle schoolers found perceived peer norms predicted substance use in younger teens, while direct exposure to substance-using peers became more influential with age.
Prospective study of 2,042 Chilean adolescents found cannabis misuse independently predicted new self-harm onset over 6 months, alongside depression, suicidal thoughts, and poor problem-solving.
THC disrupted learning-related hippocampal plasticity and neurogenesis markers in adolescent rats, but only during active training, with no effects in untrained animals.
Study of 3,146 college students found 30% had used marijuana before college and 8.5% started during freshman year, with campus residence as a key risk factor for initiation.
Review of 7 randomized trials found Project TND consistently reduced hard drug use in all trials, with less consistent effects on alcohol (4/7) and marijuana (2-3/7).
Unexposed offspring of THC-exposed rats showed compulsive heroin-seeking behavior and altered striatal brain circuitry, suggesting transgenerational epigenetic effects of parental cannabis exposure.
Mice with a genetic variant in neural cell adhesion showed delayed but lasting cognitive damage from juvenile THC exposure, while normal mice did not, supporting a gene-environment interaction.
Analysis of 72,053 high school seniors found simultaneous use of alcohol and marijuana was associated with the highest rates of unsafe driving, exceeding concurrent or single-substance use.
Study of 463 adolescents found COMT gene methylation was linked to smoking, and a specific genotype-methylation interaction influenced high-frequency cannabis use.
Adolescent monkeys given THC for 6 months showed persistent impairment in spatial working memory (still maturing) but not object working memory (already mature).
RCT of 7,079 students across 7 European countries found "Unplugged" reduced cannabis use, smoking, and drunkenness, with cannabis and alcohol effects persisting at 15 months.
RCT of 1,734 Australian students found a computer-based prevention program increased drug knowledge, decreased pro-drug attitudes, and reduced cannabis use frequency in females.
In nearly 5,000 young Swiss men, cannabis use and depression predicted later disengagement from work and school, but being disengaged did not predict later substance use.
Mice with a schizophrenia-linked gene mutation showed worsened emotional memory and reduced brain activity when exposed to THC during adolescence, demonstrating gene-environment interaction.
Among 678 young French smokers, cannabis use in the prior year and financial difficulties were the strongest barriers to sustaining tobacco cessation for 12 months.
Adolescent THC exposure affected heroin reward differently in addiction-prone vs. resilient rat strains, suggesting genetics determine whether cannabis acts as a gateway.
Among 69 young cannabis users, earlier initiation was linked to worse episodic memory in females but not males, after controlling for lifetime use, suggesting sex-specific vulnerabilities.
Survey of 8,214 middle schoolers found medical marijuana ad exposure predicted higher marijuana use and intentions one year later, with the relationship running in both directions.
Economic modeling showed a school cannabis prevention program was cost-effective generally and cost-saving (3.2:1 return) when targeted to at-risk boys over 20 years.
A 17-year-old had 5 ER visits for vomiting and weight loss before CHS was diagnosed, illustrating how underrecognized the condition is in adolescents.
Longitudinal study of 816 people found externalizing disorders (conduct problems) predicted cannabis use disorder onset from ages 16-30, while depression and anxiety did not.
A 13-year-old with cyclic vomiting had a false-positive cannabis urine screen caused by pantoprazole, highlighting a drug interaction that could lead to misdiagnosis of CHS.
35-year birth cohort study of 1,265 New Zealanders found regular cannabis use associated with lower education, unemployment, and psychotic symptoms, but many regular users experienced no harm.
Systematic review found only 3 of 42 outcome measures showed significant effects across 6 independently evaluated RCTs of school drug prevention programs, with only one program effective.
Survey of 255 French medical students found cannabis users failed exams at 89% vs. 39% for non-users, with 10% of all students reporting suicidal ideation.
Among 371 juvenile detainees, cannabis use was 54% lifetime and 16% daily, far above general population rates, with daily users showing worse mental health but not more criminal involvement.
Among 772 college freshmen, moderate drinkers who also used marijuana had significantly more blackouts, injuries, and DUIs than moderate drinkers who did not use marijuana.
Review for pediatricians found limited evidence for medical cannabis in developmental conditions and well-documented risks to the developing adolescent brain from regular cannabis use.
Heavy adolescent marijuana users showed disrupted emotional development (no improvement in negative emotionality or resilience), with brain activation differences mediating the outcomes.
Among 480 Spanish undergraduates, 46% used multiple substances with cannabis-inclusive patterns most common, and use strongly correlated with close family and friends' substance use.
Parent survey of 117 children with epilepsy reported 85% seizure reduction with CBD products, but the study authors explicitly warned of severe participation bias and lack of controls.
Survey of 1,811 young adult smokers found 46% called themselves social smokers but smoked alone too. Both social smoker groups were more likely to use and be dependent on marijuana.
School-based program targeting personality risk factors delayed cannabis use in high-risk teens, with sensation-seekers 75% less likely to start using over 24 months.
MRI study found young adult cannabis users had thinner cortex in the fusiform gyrus and smaller thalamic volumes linked to greater impulsivity compared to matched non-users.
Review found marijuana crosses the placenta and appears in breast milk, with evidence linking prenatal exposure to growth restriction and neurological development effects, though data quality is limited.
National survey data showed drug-free workplace policies and EAPs were each associated with 15% lower odds of marijuana use and prescription drug misuse in young workers.
Randomized trial of 1,874 sixth-graders showed a universal prevention program reduced cannabis use across all risk levels, with the largest absolute effect for high-risk children.
Study of 205 psychosis patients found those who previously used prescription stimulants developed psychosis four years earlier on average, independent of cannabis use or family history.
Survey of 2,002 college students found 17% allowed marijuana smoking in their homes versus 14.5% for cigarettes, with different social factors predicting each.
56% of South African teens with first-episode psychosis reported cannabis use (96% male), with an average 7-month delay before treatment began.
Among 75 children given cannabis extracts for epilepsy, parents reported 33% had seizures cut in half, with dramatic differences by syndrome type. But 44% had side effects including worsened seizures.
First-grade attention problems predicted marijuana use by seventh grade in African American youth, while externalizing behavior predicted drug exposure opportunities during the high school transition.
Study of 144 adolescent offenders in Spain found 78.5% used drugs, with psychotic teens preferring cannabis and ADHD teens gravitating toward cannabis plus cocaine.
Twin study of nearly 10,000 teens found the cannabis-psychotic experience association is driven by shared environmental factors (69-100%) rather than genetics, with cannabis explaining only 2-5% of psychotic experience variance.
fMRI study found 14-year-old cannabis users had exaggerated amygdala reactivity to angry faces and impaired cortical threat regulation compared to matched non-users.
Analysis of 36,000+ marijuana-related tweets found mostly positive attitudes among adolescents, with personal use disclosures increasing after two states legalized recreational cannabis.
Adolescent THC exposure in rats produced over 1,000 regions of altered DNA methylation in their unexposed offspring's brain reward center, affecting glutamatergic signaling genes.
Blocking CB1 receptors reduced binge alcohol and sucrose consumption in adolescent mice to adult levels, suggesting the endocannabinoid system drives age-related differences in binge drinking.
A clinical review documented the rise of synthetic cannabinoids and other designer drugs, noting unpredictable toxicity, psychosis risk, and evasion of standard drug tests.
A clinical review examined the evidence on adolescent cannabis use in the context of expanding legalization, covering risks, legal frameworks, and clinical considerations.
A policy review argued that the legal consequences of juvenile cannabis arrests (records, expulsions, loan ineligibility, racial disparities) often cause more harm than the drug itself.
In a nationally representative sample, alcohol was the most common first substance among US 12th graders, and earlier alcohol initiation predicted significantly greater illicit drug involvement.
A review found minimal evidence for prenatal cannabis exposure causing childhood aggression, and only a marginal, largely confounded association between adolescent use and aggressive behavior.
In a study of 344 Aboriginal women, 20.5% used cannabis during pregnancy, and their babies were 565g lighter with 3.9x higher odds of low birth weight after adjusting for social factors.
A neuroimaging review found marijuana use is associated with brain structure and function changes, with adolescent-onset use showing the most concerning patterns of alteration.
A 16-year-old developed a perforated duodenal ulcer after 3 years of synthetic cannabinoid use, requiring emergency surgery with successful recovery.
Among 80 rehab patients, those with ADHD started using substances earlier, and earlier cannabis onset in ADHD patients predicted more severe later cannabis and cocaine use.
Analysis of 430 US poison center calls for edible marijuana found children under 5 were most affected (25%), calls rose yearly, and 91% came from states with decriminalized cannabis.
Mothers' tobacco and alcohol use predicted earlier alcohol onset in children, while fathers' marijuana combined with alcohol use was also significant, challenging the focus on paternal risk.
Expert clinicians discussed the assessment and management of an adolescent marijuana use disorder, sharing clinical reasoning in a case conference format.
A policy review criticized simplistic youth drug prevention and recommended the IOM three-tiered model with Student Assistance Programs and stable marijuana tax funding.
An internet-based prevention program improved alcohol and cannabis knowledge in 1,103 Australian students and reduced alcohol use, but had no effect on cannabis use or cannabis intentions.
The clinical program that turned CBD into the first FDA-approved cannabis-derived drug. Open-label trial: 214 patients, 36.5% seizure reduction. NEJM RCT: 120 Dravet patients, seizures dropped from 12.4 to 5.9/month vs placebo (p=0.01). Epidiolex approved June 2018.
Analysis of 38,681 DEA-seized samples showed cannabis THC tripled from ~4% to ~12% between 1995–2014 while CBD nearly disappeared.
Among 5,677 young Swiss men, ADHD was independently associated with earlier drug initiation, riskier use patterns, and more substance disorders, even after controlling for antisocial personality.
A study of nearly 10,000 Australian twins found that while lifetime cannabis use and self-injury share genetic roots, early cannabis use before age 17 appears to carry independent risk for self-harm even after accounting for genetics.
Brain scans revealed that young cannabis users showed unique reward-region activation when following social pressure to conform, with the strength of this activation correlating with how much cannabis they used.
Cannabis-using young adults showed greater brain activation in the caudate when receiving peer information and took longer to make decisions opposing the group, suggesting heightened neural sensitivity to social influence.
Among 3,418 college students, five substance use patterns emerged, with a notably stable cluster of students who primarily co-used little cigars, hookah, and marijuana.
A survey of 2,572 Bahamian secondary school students found that both alcohol and marijuana use were independently associated with sexual behavior, supporting integrated prevention approaches.
The 2015 CDC Youth Risk Behavior Survey found 21.7% of US high school students used marijuana in the past month, a rate that had not declined over time even as cigarette and alcohol use decreased.
Among 247 first-episode psychosis patients, escalating marijuana use in the 5 years before onset was strongly linked to faster psychosis development, with daily use doubling the rate independent of other substance use.
In 16 children with severe treatment-resistant spasticity, synthetic THC (dronabinol) abolished or markedly improved spasticity in 75% of cases over months of treatment with minimal side effects.
MRI study found cannabis use was associated with thinner frontal cortex in young adults, with distinct brain structure patterns emerging in cannabis users who also had persistent ADHD.
International survey data shows synthetic cannabinoid use affects 0.2-4% of the population, peaks in late teens, is mostly experimental and curiosity-driven, with users overestimating how common it is.
Systematic review of 13 brain imaging studies found adolescent cannabis users showed altered frontal-parietal brain function during cognitive tasks while maintaining normal performance, suggesting compensatory mechanisms.
First controlled comparison found adolescents felt less stoned and had fewer memory problems from cannabis than adults, but showed impaired impulse control and no feeling of having had enough, potentially driving escalated use.
Persistent ADHD and frequent cannabis use each independently associated with thinner cortex in a key impulse control brain region in young adults.
fMRI study finds ADHD reduced impulse control brain activation regardless of cannabis use, while cannabis-using controls recruited compensatory brain regions that ADHD participants could not.
Clinical review finds insufficient evidence for medical cannabis in children overall, but acknowledges exceptional cases like refractory epilepsy may warrant carefully supervised, research-based use.
Study of 238 adolescent cannabis users found more lifetime use was linked to higher BMI and greater obesity risk, regardless of decision-making ability.
Brazilian school drug prevention program showed 85.7% of teen marijuana users in the intervention group stopped using, compared to 28.6% in controls.
Adolescent THC exposure in rats enhanced adult cannabinoid self-administration and blunted dopamine reward signaling, providing a biological mechanism for increased addiction vulnerability after early cannabis use.
Adolescent rats experiencing social rejection from unresponsive partners developed altered pain sensitivity through endocannabinoid CB1 signaling, linking social and physical pain processing.
Longitudinal study of 936 college freshmen finds pre-college marijuana use predicted hookah initiation in the first month of college, alongside alcohol as the only other predictor.
Young adults prenatally exposed to marijuana showed altered brain activation (increased left posterior activity) during executive function tasks despite normal performance, suggesting neural compensation 18-22 years after exposure.
In a teen marijuana cessation trial, NAC-treated adolescents who reduced marijuana use also reduced alcohol use, with no compensatory increase in drinking.
Among 2,508 Chilean teens, generalized anxiety was the only mental health symptom that independently predicted both starting cannabis use and using more frequently over 18 months.
Among 1,134 French college students, cannabis use was strongly associated with e-cigarette experimentation (2.44x odds), and nearly half of e-cigarette experimenters had never smoked cigarettes.
Multicenter Israeli study found 89% of 74 children with severe, treatment-resistant epilepsy (failed 7+ drugs) had seizure reduction with CBD-enriched cannabis oil, with 18% achieving 75-100% reduction.
Longitudinal study finds e-cigarette use by Hispanic young adults predicted nearly 2x higher odds of starting marijuana and 3x higher odds of starting cigarettes one year later.
Study of 2,722 Hispanic youth finds that increasing or persistently high discrimination trajectories from age 14-23 predicted higher marijuana, alcohol, and hard drug use.
Study of 5,103 Swiss men finds ADHD predicted initiating new substances (especially amphetamines) over 15 months, independent of conduct disorder, without escalating existing substance use.
Colorado pediatric marijuana exposures nearly doubled at a children's hospital and increased 5-fold at the poison center after recreational legalization, with edibles responsible for ~50% of cases.
Adolescent THC exposure produced lasting memory deficits and psychotic-like behaviors in male rats, driven by glutamate signaling disruption and neuroinflammation specifically in the hippocampus.
Cannabis-related emergency room visits in the US increased significantly from 2004 to 2011, with the steepest rises among adolescents and disproportionate representation of Black Americans.
A 25-year cohort study found childhood conduct problems and adolescent attention difficulties independently predicted problematic cannabis use by age 25.
Adolescent cannabinoid exposure in mice altered cocaine withdrawal in adulthood, preventing anxiety but worsening depressive symptoms during cocaine cessation.
College students who viewed young adulthood as a time for experimentation were more likely to use marijuana and binge drink, while those focused on identity exploration used less marijuana.
A variant in the cannabinoid receptor gene CNR1 was linked to more frequent cannabis use at age 18, but the genetic effect did not change the trajectory of use over the following six years.
Prospective study of young Mexicans found cannabis use before age 15 was associated with nearly 4x risk of suicidal ideation and 5x risk of suicide attempt over eight years of follow-up.
In a 20-year cohort study, adolescent self-harm independently predicted weekly cannabis use at age 35, the only outcome that survived adjustment for adolescent mental health and behavior problems.
Among underage drinkers in an ER sample, marijuana use more than doubled the odds of driving after drinking for females and significantly increased risk for males.
Low-dose pesticide exposure during rat development elevated endocannabinoid levels and decreased anxiety-like behavior, even at doses below traditional neurotoxicity thresholds.
Despite marijuana use doubling among Chilean teens from 2009-2013, rigorous analysis found the massive 2011 school protest movement had no causal effect on substance use.
First reported case of cannabinoid poisoning from medically prescribed hemp seed oil in a preschool child, with neurological symptoms resolving after IV hydration.
Comprehensive review finding a disconnect between cannabis's "soft drug" reputation and growing evidence of cognitive impairment, psychosis risk, and gateway effects, particularly in youth.
School connectedness and adult support reduced marijuana and other substance use among LGB youth in California, even after accounting for school victimization.
Review finding growing evidence that prenatal marijuana exposure is associated with lower birth weight, preterm birth, and impaired neurodevelopment, with THC also found in breast milk.
First reported cases of capsaicin cream successfully treating cannabinoid hyperemesis syndrome in two adolescents after standard anti-nausea treatments failed.
Canadian Paediatric Society review documenting that adolescent cannabis use causes brain changes and is associated with dependence, mental illness, cognitive decline, and academic underperformance.
Narrative review finding substantial evidence linking cannabis to psychosis and other drug use, mixed evidence for depression and anxiety, with adolescent onset carrying the greatest psychiatric risk.
Dispensary study of 217 patients finding younger medical cannabis users consume more and show more problematic use than older users, with early initiation as a key risk factor.
20-year cohort study of 1,229 people identifying distinct risk profiles for persistent (6.7%), limited (13.3%), and delayed (3.7%) problematic cannabis use, with anxiety predicting persistence and childhood trauma predicting late onset.
Large RCT across 32 Australian schools finding that a three-year resilience-building intervention produced no significant reductions in marijuana, tobacco, alcohol, or other substance use among 2,105 students.
Pediatric gastroenterologists from Colorado review the challenges of caring for children with IBD as cannabis acceptance grows, highlighting biological plausibility but insufficient evidence and developmental concerns.
Brain imaging study of 75 young adults finding that childhood ADHD and current cannabis use affect separate brain networks, with no evidence that cannabis worsens ADHD-related connectivity changes.
Longitudinal study following 20 heavy cannabis users and 23 controls for 39 months, finding no hippocampal volume differences or divergent growth trajectories, regardless of dose or age of onset.
Study of 645 meconium samples finding good agreement between maternal self-reports and objective testing for tobacco but poor agreement for cannabis and alcohol, suggesting underreporting of prenatal exposure.
Study of 366 young adults finding medical cannabis patients used more frequently and spent more than recreational users, but also vaped more and showed trends toward less prescription drug misuse.
Comprehensive review finding strong evidence from human and animal studies that adolescent cannabis exposure causes lasting deficits in cognition, emotion, and psychosis risk that do not occur with adult-onset exposure.
Longitudinal study of 158 young men finding escalating adolescent cannabis use disrupted reward-prefrontal brain connectivity, predicting more depression, anhedonia, and lower education at age 22.
Meta-analysis of 23 independent samples finding interactive school-based prevention programs produced a small but significant reduction in middle school cannabis use (d=-0.07), with teacher-delivered programs being most effective.
Critical review plus fatal case report finding strong evidence that chronic cannabis use damages brain white matter and impairs cognition, with few objective data supporting cannabis over conventional therapies for neurological conditions.
Study of 260 first-episode psychosis patients finding early cannabis use and BDNF met-allele independently predicted younger psychosis onset, with early cannabis use more common in males.
Analysis of 12 million treatment records finding increasing youth marijuana admissions from 1995-2012 alongside dramatically decreasing drug severity, suggesting lower referral thresholds rather than worsening problems.
Analysis of national data finding rising Hispanic youth marijuana treatment admissions from 1995-2012, with female admissions growing faster than male, linked more to school/community referrals than severe drug problems.
Review of neuroimaging evidence showing cannabis and alcohol alter adolescent brain development, with most cognitive effects resolving after abstinence but attentional deficits persisting.
Monitoring the Future data showing college became a dramatically stronger risk factor for marijuana initiation after 2013, with 51% increased risk by 2015 compared to 17-22% historically.
Review of CBD for treatment-resistant epilepsy showing Phase 3 RCT evidence of efficacy for Dravet and Lennox-Gastaut syndromes, while highlighting the gap between pharmaceutical CBD and unvalidated dispensary products.
Longitudinal study of 711 people showing cannabis use at 17 led to drug-using friendships at 22, which predicted starting cocaine, meth, or opiates by 27, supporting a social rather than pharmacological gateway mechanism.
Animal study found that both caffeine and cannabis altered neurotransmitter and enzyme levels in juvenile rat brains, with their combination producing amplified metabolic effects.
Case-control study found that adolescents with first-episode psychosis and a family history of psychosis actually had milder positive symptoms at onset, challenging assumptions about genetic risk.
Large survey of nearly 39,000 Asian adolescents found cannabis use under 1%, with cigarette smoking the only universal predictor across all five countries studied.
Qualitative study of 32 young adults in Colorado found they evaluate cannabis and tobacco risks through five lenses: combustion, potency, chemicals, addiction type, and information sources.
Survey of 6,089 Hawaiian teens found e-cigarette use independently associated with asthma (aOR 1.48), while marijuana and cigarette use were not significant after controlling for e-cigarettes.
Longitudinal study of 2,539 teens found neighborhood drug problems predicted marijuana use, but personal resistance confidence and avoiding drug-using peers buffered these effects.
Lab study using human-derived neurons found high-dose THC (10 micromolar) disrupted neuronal function during dopaminergic development, while low doses had minimal effects.
Survey of 22,224 Mexican university students found earlier substance initiation predicted current use and polysubstance use, with males significantly more likely to use marijuana.
Pilot trial found a family-based intervention with emotional regulation skills reduced marijuana use and risky behaviors among justice-involved youth over 3 months.
Chart review of 119 pediatric epilepsy patients found 71% discontinued cannabis extracts, with only 13% achieving greater than 50% seizure reduction and perceived benefit the sole predictor of continued use.
Survey of 7,488 African American students found 18.5% past-year marijuana use, with parent, teacher, and school protective factors significantly reducing risk.
16-year MTA study follow-up found ADHD did not increase psychosis risk (5% vs. 4%), but cannabis use was significantly associated with psychotic symptoms in both groups.
Review of cannabis legalization's unintended pediatric consequences, covering prenatal exposure, accidental childhood ingestion, adolescent use, and the need for rigorous CBD epilepsy trials.
Study of 43 hospitalized Colorado toddlers found 16% had detectable marijuana metabolites, with higher rates in non-white children and those exposed to tobacco smoke.
Review of 98 reported cases found cannabinoid-related strokes mainly affected young male chronic users, with reversible vasoconstriction as a proposed mechanism in 27% of cases.
Systematic review of 22 studies found strongest pediatric evidence for chemotherapy-induced nausea, increasing evidence for epilepsy, and insufficient evidence for other conditions.
Patients with psychosis who used cannabis heavily before illness had higher schizophrenia polygenic risk scores, with the largest effect in those who started before age 18.
Psychotic patients with adolescent cannabis use showed less gray matter loss than those without, suggesting cannabis-associated psychosis may be a distinct subtype with less underlying brain pathology.
Adolescent synthetic cannabinoid exposure triggered schizophrenia-like dopamine changes in genetically susceptible rats but not in non-susceptible rats, modeling the human gene-environment interaction.
Early-onset cannabis users (before age 18) performed worse on a gambling task than late-onset users and non-users, with decision-making driven by short-term gains rather than loss avoidance.
Interviews with 30 teens found marijuana blunt use frequently led to standalone cigarillo tobacco smoking, with group sharing and substitution driving co-use.
A culturally tailored HIV prevention program reduced marijuana initiation risk by 17.3% among American Indian middle schoolers, though it did not reduce use frequency among initiators.
Brain imaging of 59 young men found early cannabis use altered hippocampal subregion volumes, with effects modified by the DAT1 dopamine transporter gene variant.
Meta-analysis of 20 fMRI studies found cannabis users show altered brain activation patterns, with different changes in adults (temporal/frontal regions) versus adolescents (parietal/putamen).
Adults with ADHD used cannabis at 3x the rate of those without, with the hyperactive subtype starting at age 13.8 versus 16.3 for inattentive, and 4x higher personality disorder rates.
Survey of 52 young MS patients found 48% used marijuana for relaxation and symptoms, with 64% of users acknowledging negative memory and focus effects.
Among 1,313 college freshmen, 5.9% started vaping cannabis during their first year, driven specifically by peers who also started vaping cannabis rather than general cannabis or e-cigarette users.
Online school program reduced teenagers' intentions to use synthetic cannabis by 2 years, with controls 3.5x more likely to intend use, but only when all 4 lessons were completed.
Mice with a schizophrenia risk gene showed normal endocannabinoid system development across 8 time points, suggesting their heightened cannabis sensitivity operates through other mechanisms.
Longitudinal study of 1,023 teens found parental restriction of R-rated movies protective against marijuana and alcohol initiation, with supervised viewing also offering protection.
In legalized Colorado, 5.7% of pregnant women used cannabis, with a 50% increased risk of low birth weight independent of tobacco, though preterm birth and NICU rates were not elevated.
Boosting endocannabinoid levels with a FAAH inhibitor reversed depressive behavior, restored synaptic plasticity, and rescued neurogenesis damaged by adolescent THC in female rats.
Analysis of 550 tweets found most discussion of marijuana and pregnancy was neutral in tone, while linked sources focused on negative outcomes like impaired brain development and low birth weight.
Overview found cannabinoids produce dose-dependent acute effects on anxiety, mood, and cognition, with chronic use linked to tolerance, dependence, withdrawal, and associations with psychiatric disorders.
Rural college students started with lower marijuana use than urban peers as freshmen but matched their rates by junior year, with perceived peer use as the strongest predictor of escalation.
Longitudinal study of 247 families found prenatal tobacco effects were stronger in girls, and a bidirectional cycle where toddler behavior problems predicted increased maternal cannabis use.
Twin study of 3,762 adolescents found childhood ADHD predicted earlier marijuana use, but identical twin analysis indicated shared genetics, not ADHD itself, primarily drive the link.
National survey found parental cannabis use rose from 4.9% to 6.8% (2002-2015) while cigarette smoking declined, with cannabis use nearly 4 times higher among smoking parents.
Analysis of five states found cannabis decriminalization cut youth drug arrests by 75% with no increase in past-30-day youth cannabis use, achieving intended consequences without feared side effects.
THC exposure dampened human neuron gene responses to stimulation, with changes in synaptic and glutamate pathways overlapping schizophrenia, autism, and intellectual disability gene patterns.
Major review documented US increases in cannabis potency, use disorders, ER visits, and fatal crashes alongside growing perception of harmlessness, while medical marijuana laws showed no effect on adolescent use.
Observational study found 56% of children with treatment-resistant epilepsy achieved 50%+ seizure reduction with CBD-enriched cannabis oil (20:1 ratio), with younger age and higher doses predicting better response.
Pilot study of 25 adolescent psychiatric inpatients found 76% substance use and 36% illicit drug use, with cannabis predicted by family dysfunction and substance use linked to suicidal ideation.
Longitudinal study found higher schizophrenia genetic risk predicted stronger cannabis use increases during ages 16-20, with no relationship to alcohol or tobacco, supporting shared genetics between schizophrenia and cannabis use.
Mouse study found chronic THC rewired serotonin receptors toward a pro-psychotic signaling pattern via the Akt/mTOR pathway. Rapamycin blocked the effect.
Longitudinal study of 69 youth found alcohol-only users showed greater brain surface area decreases in the orbitofrontal cortex than those who used both alcohol and cannabis.
Selective breeding study found adolescent THC sensitivity in mice was heritable and genetically linked to anxiety-like behavior, pointing to shared genetic factors between cannabis response and anxiety.
Pilot study of 25 children with complex motor disorders found CBD-enriched cannabis oil improved spasticity, dystonia, sleep, pain, and quality of life over 5 months, with rare adverse effects.
Human Connectome Project analysis found cannabis-dependent individuals had hyperconnectivity in dopamine-related brain regions (striatum, midbrain), most pronounced in those who started youngest and reported high negative emotionality.
Study of 721 college users found tobacco-marijuana co-users prioritized quitting cigarettes over marijuana, with higher importance ratings but lower confidence for cigarette cessation. Different factors predicted quitting each substance.
Open-label trial of 20 Dravet syndrome children found CBD/THC cannabis oil achieved 70.6% median seizure reduction and 63% responder rate, with significant quality of life improvement over 20 weeks.
Study of 459 SUD patients found a graded pattern: childhood trauma plus PTSD showed the worst cannabis and psychiatric outcomes, trauma-only was intermediate, and no-trauma had the best outcomes.
Obstetrics review found marijuana crosses the placenta and enters breast milk, with meta-analyses and cohort studies suggesting associations with growth restriction, preterm birth, and neurobehavioral effects. Women advised to avoid use during pregnancy and lactation.
Largest GWAS of cannabis initiation timing found 38% heritability and identified ATP2C2 (calcium signaling gene) as a candidate, linking cannabis initiation to the same pathway implicated in cocaine and opioid dependence.
Cluster RCT of 2,190 Australian students found school-based prevention programs increased cannabis knowledge for 2 years, but effects on actual cannabis use and harms were inconclusive over 3 years.
Review of 66 studies concluded cannabis doubles psychosis risk in vulnerable individuals, with dose-response and age-of-first-use effects, and gene-environment interactions modulating individual susceptibility.
National database analysis found heart attack admissions among cannabis users rose 32% from 2010-2014, with in-hospital mortality up 60%, predominantly in males averaging age 41.
ADHD adolescents with cannabis use disorder had higher hospital costs, longer stays, and 17-fold higher alcohol abuse risk, but received 55% less psychiatric medication and 59% less behavioral therapy.
Study of 247 first-episode psychosis patients found cigarette smoking age, poor childhood academics/sociability, and trauma all predicted heavier premorbid marijuana use before psychosis onset.
Survey of 3,177 LA tenth-graders found high cannabis use across methods (31% combustible, 21% edible, 11% vaporized), with most users consuming via multiple administration methods.
Retrospective study of 108 children found artisanal CBD oil achieved >50% seizure reduction in 39%, with 10% seizure-free, 14% showing improved alertness, and minimal side effects.
THC during adolescence caused epigenetic changes in rat brains that altered gene activity and led to cognitive deficits - effects not seen with adult exposure. Blocking the changes prevented cognitive harm.
Ten-year study of 481 street-involved youth found daily cannabis users were 34% less likely to start injecting drugs, challenging the gateway drug hypothesis.
Review of preclinical evidence explains how adolescent THC exposure may disrupt the brain's inhibitory GABA system in the prefrontal cortex, potentially triggering schizophrenia-like dopamine dysregulation.
French university students with ADHD (5.6%) had significantly higher rates of cannabis, alcohol, and tobacco use plus behavioral addictions, and were more likely to struggle academically.
Review highlights that while CBD treats childhood epilepsy effectively, the endocannabinoid system plays critical roles in brain development, and long-term effects of modulating it in children remain unknown.
Meta-analysis of 69 studies found cannabis cognitive deficits are small (d=-0.25) and become non-significant after 72 hours of abstinence — meaning most impairment is residual drug effect, not lasting damage.
The reasons teens gave for starting cannabis - seeking sedation, stimulation, social acceptance, or recreation - predicted their schizophrenia risk and symptom severity.
Smartphone tracking found that 73.5% of young heavy cannabis users lapsed during attempted abstinence, with negative expectations, low family support, and permissive environments predicting relapse.
Review reveals that cannabis exposure during development can create lasting epigenetic changes - modifications to gene expression that persist across the lifespan and have been observed transmitting to the next generation.
Adults who started cannabis earlier had slower reaction times at 28 due to reduced brain encoding activation, but the same pattern appeared after single use, suggesting pre-existing differences rather than drug-caused damage.
Prospective brain imaging found that neurocognitive differences attributed to early cannabis use actually existed at age 12, before any cannabis use began, supporting a pre-existing risk model.
Marijuana-related ER visits by teens at a Colorado children's hospital nearly tripled after legalization (1.8 to 4.9 per 1,000 visits), with most involving psychiatric diagnoses, despite surveys showing no increase in use.
46% of hospitalized children of smoking parents in Colorado had marijuana metabolites in their urine, with 11% having detectable THC itself. Home marijuana use by parents was the strongest predictor.
Rats given escalating THC during adolescence showed learning delays and sensorimotor gating impairments as adults, but both deficits appeared to diminish over time, suggesting partial neural recovery.
A review of cannabis evidence for autism found only five small studies and mixed results for all conditions except epilepsy, highlighting a major gap between anecdotal reports and scientific evidence.
Three randomized controlled trials showed CBD reduced seizures by 38-41% in severe childhood epilepsies, performing comparably to established anti-epileptic drugs with manageable side effects.
CBD and clobazam work better together through two mechanisms: CBD raises clobazam blood levels AND both drugs together directly enhance GABA receptor inhibition, providing genuine therapeutic synergy.
Adolescents in the ED after synthetic cannabinoid use had 3.4x higher odds of coma and 3.9x higher odds of seizures than those using traditional cannabis, showing a distinct and more dangerous toxicity profile.
In 60 children with autism and severe behavioral problems, CBD-rich cannabis improved behavioral outbreaks in 61% with mostly mild side effects, supporting feasibility of controlled trials.
Focus groups with 37 cannabis-using teens identified rewards, self-monitoring, peer support, privacy, and customizable notifications as key elements for an engaging cessation app.
In a prospective study of 188 autism patients treated with CBD-rich cannabis oil for six months, 84% of those assessed reported improvement, with mostly mild side effects and high treatment continuation.
A comprehensive review details how alcohol alters the endocannabinoid system to drive addiction, how CB1 receptors contribute to alcohol reward, and how ECS disruption contributes to fetal alcohol spectrum disorders.
High-sensitivity testing found 25% of urban teens positive for THC, far more than standard tests detected. Cigarette smokers had 13x the odds of marijuana use.
An RCT found weekly text messages to parents about school performance reduced teen alcohol and marijuana initiation from 18.2% to 10.2% by 8th grade, at just $15/student/year.
Epidiolex became the first CBD medication approved by a national regulator, earning FDA approval for Dravet and Lennox-Gastaut syndromes based on Phase III clinical trials.
Cannabis users with two copies of a specific FAAH gene variant had 10x higher odds of a first psychotic episode, identifying a gene-environment interaction that could explain selective psychosis risk.
An fMRI study found adolescent cannabis use disorder was linked to reduced brain activation in threat-processing regions including the amygdala, an effect not seen with alcohol use disorder.
A meta-analysis found altered brain network function in teen cannabis users even after 25+ days of abstinence, when cognitive test performance had already recovered.
A review found increasing pediatric hospitalizations from high-potency cannabis products like edibles, causing sedation and respiratory depression in young children, while chronic teen use causes cognitive and GI problems.
A comprehensive neuroimaging review found cannabis affects executive, emotional, reward, and memory brain systems through direct and indirect pathways, with adolescent use carrying particular risk for lasting changes.
Among young adults with psychosis, cannabis users and non-users showed no cognitive differences at illness onset, suggesting cannabis may trigger psychosis in individuals who would not otherwise develop it.
Cannabis use predicted suicidal ideation, planning, and attempts in 451 Latinx LGB teens, with the strongest association (OR 3.12) for actual suicide attempts.
Prenatal cannabinoid exposure in rats accelerated early motor development but worsened alcohol-related motor impairment specifically in females, with combined exposure showing complex interactions.
Adolescent cannabis smoke and THC exposure in rats produced no lasting anxiety, depression, or cognitive effects in adulthood, suggesting human associations may involve non-cannabinoid factors.
A randomized trial found online responsible vendor training for marijuana stores improved ID checking skills and intoxication detection confidence, with 91% of employees recommending it.
A review found substantial evidence that cannabis affects brain structure and cognition, particularly during adolescence, while paradoxically some cannabinoid compounds are approved for medical use in children.
A study of 86,254 teens across 21 countries found cannabis use approximately doubled the odds of suicide attempts, with the association consistent across countries with widely varying cannabis prevalence.
A review for pediatric gynecologists found adolescent marijuana use carries risks for brain development, reproductive health, and mental health, with limited research on gynecological-specific effects.
Epidiolex (pure CBD) reduced severe seizures by 17-23% over placebo in children with Dravet and Lennox-Gastaut syndromes, with key drug interactions requiring careful management.
Cannabis-related pediatric ER visits are rising, ranging from accidental ingestion (hyperkinesis, coma in young children) to chronic hyperemesis and psychosis in adolescents.
Among 12,642 teens, bullies and bully-victims had higher marijuana use, but stronger parent and peer attachments significantly reduced this risk, suggesting targets for prevention programs.
Adolescent synthetic cannabinoid users had thinner frontal cortex than controls, with ADHD comorbidity producing additional brain changes, suggesting interactive effects on the developing brain.
Antipsychotic-naive psychosis patients with recent cannabis use showed more excitement symptoms initially but responded better to treatment at 10 weeks, suggesting a potentially more treatable psychosis subtype.
Cannabis-using youth showed weaker frontostriatal brain circuit activation during cognitive conflict tasks, suggesting self-regulation circuit changes appear early in the course of cannabis use.
A review found growing evidence for cannabis-based treatments in CDKL5 Deficiency Disorder, including an open-label trial showing seizure reduction, building on proven CBD efficacy in similar severe epilepsies.
Review exploring how combined alcohol and cannabis exposure alters gene activity through epigenetic mechanisms across different life stages, with potential for lasting and even intergenerational effects.
Systematic review of 23 studies finds moderate-certainty evidence that pharmaceutical CBD reduces seizure frequency by about 20% in children with drug-resistant epilepsy, with diarrhea as the main side effect.
Longitudinal study of 4,975 young men found ADHD predicted persistent risky alcohol and nicotine use but was associated with maturing out of risky cannabis use over 15 months.
Study of 366 young LA cannabis users found self-reported medical use linked to less illicit drug use, while concentrate and edible use predicted more other drug use, regardless of frequency.
Analysis of the landmark ABCD study found prenatal cannabis exposure associated with increased psychosis proneness in children, especially when mothers continued use after knowing they were pregnant.
Study of 500 college students finds the MAOA gene interacts with childhood abuse to predict cannabis and tobacco use in sex-opposite patterns: high-activity variants matter in women, low-activity in men.
Observational study of 18 autism patients found CBD-rich cannabis extract (75:1 CBD:THC) improved symptoms in 14 of 15 who completed 6-9 months of treatment, with strongest gains in seizures, ADHD, sleep, and social interaction.
Study of 5,622 Canadian youth found depression, anxiety, and drug disorders linked to being out of school and work, but cannabis use disorder showed no association at all.
Meta-analysis of 23,317 individuals found adolescent cannabis use linked to 37% higher depression risk and 3.46x higher suicide attempt risk in young adulthood, even after accounting for pre-existing mental health.
Experiment with 27,000+ participants found plain packaging and health warnings reduce cannabis product appeal, with edible gummies being the most youth-appealing product type.
Systematic review comparing adolescent and adult cannabis users suggests teens may be more vulnerable to executive function deficits, especially heavy users, but these effects may reverse with sustained abstinence.
Washington State data shows marijuana use declined among younger teens after legalization but increased among working 12th graders relative to non-working peers, especially those working more hours.
Review finds cannabis shows anti-inflammatory potential for IBD, but evidence is insufficient to recommend use in pediatric patients, calling for pediatric-specific safety and efficacy studies.
Lancet review finds cannabis legalization associated with increased use and road crash concerns, warns commercial cannabis industries may resist effective regulation like alcohol and tobacco, and outlines harm-minimizing policy approaches.
Study of 401 at-risk teens found 74% maintained low cannabis use, with boys more likely to show chronic or escalating patterns and conduct disorder showing the strongest bidirectional link to problematic use.
Review for fetal/neonatal specialists covers how the endocannabinoid system guides brain development and why exogenous cannabinoids during pregnancy, infancy, or adolescence can disrupt normal neural development.
Study of young IBD patients found 15 cannabis oil users had similar clinical profiles to 67 non-users but reported perceived benefits for sleep, nausea, and appetite, with most also using other cannabis forms.
Rat study shows adolescent cannabinoid exposure produces lasting reductions in prefrontal cortex activity during reward processing in adulthood, suggesting disrupted brain maturation.
Prospective neuroimaging studies find recency, frequency, and age of onset of teen cannabis use predict brain health outcomes, with preexisting brain differences also contributing to vulnerability.
Study of 1,661 Australian teens found 10% used multiple substances, with depression, conduct problems, and school environment as the strongest predictors, suggesting prevention should target mental health.
Mouse study shows adolescent THC only caused lasting memory impairment when combined with genetic vulnerability in astrocytes (support cells), operating through an inflammatory pathway blockable by a COX-2 inhibitor.
First US adolescent fMRI cannabis cue study shows 41 cannabis-using youth had heightened brain activation to cannabis images in reward and attention regions.
Substudy of 37 cannabis-using youth found approach avoidance training that reduced cannabis use in a larger trial did not significantly change brain cue reactivity on fMRI, with only trend-level effects.
Motivational therapy sessions with 56 frequent cannabis-using teens found emotional coping was the main use driver, with most identifying education, career, and family as values they saw cannabis use conflicting with.
Pilot RCT found computer-based screening and brief counseling in pediatric visits reduced teen cannabis use by 38% and riding with impaired drivers by 42% over 12 months.
Prospective study found only 24% of children with refractory epilepsy responded to artisanal cannabis extracts, matching placebo rates from pharmaceutical CBD trials.
Review of multiple evidence types consistently links cannabinoid exposure to persistent cognitive deficits and psychosis risk, with adolescence as a critical vulnerability window.
Review examines CBD as the first new class of antiepileptic drugs, with clinical evidence supporting its use as adjunctive treatment for Lennox-Gastaut and Dravet syndromes.
Expanded access program showed add-on CBD reduced major motor seizures by 50% at 12 weeks, sustained through 96 weeks, in patients with LGS or Dravet syndrome.
Adolescent THC unexpectedly attenuated dopamine dysfunction caused by prenatal immune activation in rats, challenging the simple two-hit model of schizophrenia.
Theoretical adverse outcome pathway proposes that cannabis contaminated with organophosphate pesticides may compound developmental neurotoxicity through overlapping molecular targets.
The Newton screen demonstrated 93% sensitivity and specificity for cannabis use disorder in 4,898 adolescents across 16 pediatric emergency departments.
Meta-analysis of 30 neuroimaging studies found regular cannabis users have significantly smaller hippocampus and orbitofrontal cortex volumes.
Birth cohort study found cannabis use at 16 approximately doubled the odds of a first suicide attempt by 21 among adolescents with suicidal thoughts or self-harm.
Survey of 1,140 college students found 7.9% used synthetic cannabinoids, driven by legality and drug test avoidance, with natural cannabis users at 7.6x higher odds.
Prospective study following boys from age 13 to their 30s found no association between adolescent cannabis use patterns and adult brain structure in 14 regions.
Longitudinal study of 500 adolescents found marijuana use caused BDNF alterations (not vice versa), with age of onset influencing the pattern of neurotrophin changes.
Adolescent THC caused premature dendritic pruning and altered gene networks in rat PFC neurons, with dysregulated networks overlapping schizophrenia-associated pathways.
Phase II trial of CBD gelatin bead formulation (PTL-101) showed 82% seizure reduction in children with treatment-resistant epilepsy, with 56% achieving 50%+ improvement.
Population study of 3,826 adolescents found cannabis caused lasting cognitive deficits in inhibitory control and working memory, with effects independent of and more pronounced than alcohol.
Two longitudinal studies found that parental cannabis use was associated with higher rates of cannabis use in their children, from adolescence through young adulthood.
The 2019 EVALI outbreak caused 805 lung injury cases and 12 deaths. Over three-quarters of patients with substance data reported using THC vaping products.
In 29 children with severe epilepsy, purified CBD reduced seizures by 50% or more in 38% of patients, with mild side effects and no worsening in any patient.
Prenatal cannabis exposure alters dopamine, serotonin, GABA, and other neurotransmitter systems in offspring, with effects that vary by brain region and sex.
Indoor cannabis smoking was associated with higher air particle levels and a non-significant trend toward worse child health outcomes in homes where tobacco was already smoked.
Since legalization, Colorado has seen increases in psychosis, suicide, substance abuse, motor vehicle fatalities, pediatric exposures, and other harms.
A Washington roadside survey found drivers with children were far less likely to drink but just as likely to test positive for THC.
Over four years, CBD helped 27% of children with severe epilepsy (3 became seizure-free), but 81% had side effects and most discontinued.
Neither THC nor stress alone caused lasting anxiety-like brain changes, but the combination during adolescence impaired fear extinction in adult mice.
In young adult regular cannabis users, the strongest predictors of use disorder severity were use frequency, beliefs about cannabis impairing cognition, perceived cognitive deficits, and anxiety.
Among young injured drivers in Arizona, 30% tested positive for THC and 19% for alcohol, with substance users less likely to use safety equipment.
Among Canadian university students, 11% used cannabis medicinally (mostly for mental health), 38% replaced prescribed medications, and 14% met criteria for cannabis use disorder.
CBD given during adolescence prevented schizophrenia-like symptoms and normalized cannabinoid receptor changes in a rat model, while haloperidol did not.
Five years into legal cannabis, Colorado stakeholders identified gaps between youth protection goals and real-world enforcement.
Ten-year Canadian study found chronic and increasing cannabis users were most likely to drive impaired as young adults.
A 12-year-old boy with severe Tourette syndrome experienced near-complete tic remission with vaporized cannabis and oral THC, with no adverse effects reported.
National survey found school disengagement predicted marijuana use in Black teens of both sexes, but perceived peer use was 8x risk for females vs 3.5x for males.
Study of 72 young people found cannabis use predicted slower attention, and subclinical ADHD symptoms did not explain this deficit.
Survey of 7,105 college students found higher marijuana use in medical marijuana states, with less than 30% of all students viewing it as a health risk.
Cannabis poison control calls for children and teens in Massachusetts increased 140% after medical marijuana legalization, with rising edible exposures.
Survey of 595 parents of chronically ill teens found those in more permissive marijuana states perceived less risk and were more likely to report their child had used marijuana.
Review of pediatric cannabis toxicity finds rising unintentional exposures with potential for serious effects including coma and respiratory depression.
Review finds strong evidence for pure CBD in specific childhood epilepsies but notes most pediatric use involves artisanal products with less evidence.
Adolescent rat study found THC given after concussions reduced anxiety, depression, and memory deficits, but THC before injury had no effect.
A cannabinoid agonist that improved fear extinction in adult rats impaired it in adolescent and juvenile rats, with younger animals showing higher CB1 receptor levels in brain regions tied to fear processing.
A narrative review found consistent evidence linking adolescent cannabis use to alterations in brain structure, function, and connectivity, with some changes appearing to persist into adulthood.
A longitudinal study of 1,606 Quebec adolescents found depression predicted subsequent weekly cannabis use, while the link between cannabis and suicidal ideation was fully explained by other substance use.
Adolescent rat offspring exposed to THC during fetal development showed impaired emotional memory, reduced neuropeptide Y neurons, and increased alcohol-seeking behavior, suggesting prenatal THC may create lasting vulnerability.
A mouse model of a human FAAH gene variant showed that adolescent females had enhanced dopamine reward circuitry and stronger THC preference that lasted into adulthood, while males were unaffected.
In a large NAPLS study of 543 individuals at clinical high risk for psychosis, slower startle responses predicted psychotic conversion (especially in females), and cannabis use showed opposite effects on sensory gating compared to healthy controls.
A cross-sectional study of 1,462 Colombian high school students found lifetime cannabis use associated with 1.88 times the odds of high suicide risk, though the study could not determine direction of the relationship.
A prospective study of 49 children with drug-resistant epilepsy in Argentina found 80% responded to add-on CBD therapy, with a median 66% seizure reduction and mild side effects.
A Canadian survey of 14,520 high school students found a strong dose-response relationship between perceived cannabis risk and impaired driving, with low-risk perceivers far more likely to drive or ride high.
Before cannabis legalization, a Canadian pediatric hospital saw 114 cannabis poisonings over 3 years. Most involved teens using cannabis with other substances, while rare accidental ingestions by toddlers all involved family-owned cannabis at home.
A 30-day mobile monitoring study of 60 young adults found slight but significant cognitive slowing and accuracy decreases on phone-based tasks when participants reported being high from marijuana.
A review of 63 neuroimaging studies found adolescent cannabis users show altered frontoparietal brain structure and function, but adult studies examining onset age gave mixed results, leaving the question of adolescent-specific vulnerability unresolved.
Among 503,000+ Ontario births, prenatal cannabis exposure was associated with 51% higher autism diagnosis rate in offspring (HR 1.51), though residual confounding cannot be excluded.
Both activating and blocking cannabinoid receptors during early adolescence impaired sociability in rats, suggesting the endocannabinoid system must be precisely balanced for normal social development. Effects were transient.
A multicenter study of 125 children found slow CBD titration achieved 38% with 50%+ seizure reduction at 6 months with better tolerability than previous faster protocols. Clobazam did not add efficacy but increased some side effects.
Non-intoxicated heavy cannabis users showed impaired simulated driving, but only those who started regular use before age 16. Late-onset users performed similarly to non-using controls.
A review found THC disrupts neuronal growth factor production through CB1 receptors, with adolescent brains showing different structural and behavioral effects than adult brains, compounded by decades of increasing THC potency.
A review of animal models found adolescent cannabis exposure interacted synergistically with early-life maternal deprivation and immune activation to produce schizophrenia-like outcomes, with important sex differences.
Combining cannabis and the anabolic steroid nandrolone in adolescent rats produced synergistic neurotoxicity: worse cognition, more anxiety and aggression, and greater brain damage through oxidative stress and apoptosis.
Cross-sectional study of Canadian students found feeling connected (relatedness) and capable (competence) were linked to less cannabis and alcohol use, while autonomy was linked to more use.
Longitudinal study of 301 young adult cannabis users found self-reported medical use was linked to lower illicit drug use, while concentrate and edible use was linked to higher drug use trajectories.
Survey of over 26,000 Oregon students found about 75% reported seeing marijuana advertising in the past month after retail legalization, mostly on storefronts and online.
Pilot study of 10 young epilepsy patients found a THC/CBD cannabis preparation was generally safe, with blood levels correlating to dose, supporting the feasibility of therapeutic drug monitoring.
Ontario study found frequent cannabis use in youth aged 12-17 was associated with elevated anxiety, depression, and behavioral symptoms, with associations 2-3 times stronger in girls than boys.
Review finds prenatal cannabis exposure is not linked to a unique birth defect pattern but is associated with impaired attention and memory, plus increased depression, anxiety, and delinquency in offspring.
National survey of nearly 88,000 adolescents found cannabis use linked to higher depression and suicide attempts, but the relationship between use frequency and depression was unexpectedly non-linear.
Survey of 166 Iranian university students found that personal attitudes and perceived control, not peer pressure, were the strongest predictors of marijuana use intentions.
fMRI study of 54 young adults found that those at higher risk for cannabis use disorder showed stronger brain activation in reward regions when exposed to cannabis odor cues.
First Korean study of CBD for childhood epilepsy found about one-third of Lennox-Gastaut and Dravet syndrome patients achieved 50%+ seizure reduction at 3 months, with mostly mild side effects.
Review found early evidence that medical cannabis may help behavioral symptoms in children with autism or fetal alcohol spectrum disorder, and severe nausea in pregnancy, but data remain very limited.
Rats exposed to cannabinoid agonist during adolescence showed persistent sleep disruption in adulthood, with decreased wakefulness and increased REM sleep.
Among 938 young adults with first-episode psychosis, one-third had persistent cannabis use at 1 year with worse symptoms, while those who reduced use showed significant improvement.
Review found prenatal cannabis exposure associated with lower birth weight, neonatal effects, and developmental delays in the first 2 years, with significant research gaps remaining.
Survey of 4,078 Nigerian adolescents found friend drug use, parental smoking, low risk perception, and positive drug beliefs predicted cannabis and illicit drug use.
In 112 rats, prior nicotine exposure altered THC brain effects depending on age and sex: adult males showed reduced THC response while adolescent females showed potentiated effects.
Review plus clinical experience found early evidence that cannabis and CBD may help ASD symptoms and comorbidities, but large controlled trials are needed.
Prospective study of 265 early psychosis patients found starting cannabis before age 15 was associated with 4.5 times higher odds of violent behavior.
Analysis of 27M pediatric hospitalizations found cannabis use disorder 68% more common in prescription opioid overdose cases, alongside high rates of mood disorders.
Georgia expanded access program found sustained seizure reduction over 36 months in 45 children with treatment-resistant epilepsy on CBD, with adverse events decreasing over time.
Study of 1,000 adults found psychosis warnings on cannabis packaging were most educational and best for discouraging youth use; any warning increased perceived harm.
In 3 infants with rare KCNT1 epilepsy, CBD showed limited benefit: 2 had no response, 1 had reduced seizure intensity and possible developmental progress.
Prospective study of 2,327 college students found dual cigarette/e-cigarette use predicted marijuana vaping initiation, while vape shop social networks predicted escalation.
A 15-year-old with autism showed unexpected improvements in core social deficits, anxiety, and sleep on low-dose CBD extract originally prescribed for epilepsy.
A 9-year-old with Lennox-Gastaut syndrome achieved complete seizure control and dramatic EEG normalization on CBD, an improvement not previously described.
Eleven-year study of 1,457 Hispanic youth found high school discrimination predicted marijuana use initiation and continuation into emerging adulthood.
Systematic review found prenatal cannabis exposure may be linked to ADHD and affective symptoms in offspring, but the topic is under-researched despite common use.
Case of a long-time marijuana user who developed paranoid psychosis within one month of switching to "dabs" with up to 80% THC.
Study of 8,323 cannabis diversion participants found African Americans and Latinos had significantly lower program completion rates, with males overrepresented at 80%.
PNAS study found adolescent cannabinoid exposure reprogrammed the rat brain response to cocaine at epigenomic, transcriptomic, and proteomic levels, specifically during adolescence.
Study of 852 adolescents found childhood cigarette/alcohol use and family factors in fifth grade predicted cannabis use patterns through age 19.
THC altered DNA methylation at 7 neurodevelopmental genes in rat sperm, overlapping with nicotine effects and enriched for autism candidate genes.
Case report of lithium toxicity developing weeks after adding CBD, revealing a previously unknown drug interaction in a patient who subsequently became seizure-free on CBD alone.
IMAGEN study found right amygdala hyper-reactivity at age 14 predicted cannabis use at 19 in a dose-response pattern, with cannabis exposure altering normal amygdala development.
Postmortem brain study found CB1 receptor expression is highest fetally, drops after birth, is decreased in schizophrenia, and follows a COMT-genotype-dependent trajectory.
An open-label study of 38 children with treatment-resistant epilepsy found no cognitive decline after one year of add-on CBD treatment, with some trends toward improvement.
A survey of 9,024 US teens found marijuana advertising was linked to use, but perceived ease of access and age were much stronger predictors and amplified the advertising effect.
Colorado poison center data showed marijuana exposure calls stabilized after 2014 legalization overall but continued rising in children ages 0-8, driven by edible products.
A survey of families with children who have PKAN found 39% used cannabis products after other treatments failed, with most reporting improvements in dystonia, pain, and sleep.
Among nearly 12,000 children in the ABCD Study, prenatal cannabis exposure was associated with multiple sleep disturbances at ages 9-10, even after controlling for other prenatal exposures.
A longitudinal brain imaging study of 706 teens found that cannabis-related psychotic-like experiences were partially mediated by reduced growth of the uncus in the parahippocampal gyrus between ages 14 and 19.
Review found legalization increased cannabis potency and ER visits while decreasing risk perception, arguing for health-focused regulation beyond market economics.
A longitudinal study of 91,774 Canadian high school students found few cannabis users quit spontaneously, but those who did showed 2.5x better attendance and 2.3x better homework completion than continuing users.
Longitudinal MRI study of 799 European teenagers found dose-dependent prefrontal cortical thinning associated with cannabis use from age 14 to 19, concentrated in CB1 receptor-rich brain regions.
A meta-analysis of brain imaging studies found no significant gray matter volume differences between cannabis-using and non-using teens, but age and sex influenced subtle, region-specific patterns.
A systematic review found moderate evidence that THC reduces speed, headway distance, and reaction time while increasing lane variability in young drivers ages 15-24.
A longitudinal study found an epigenetic biomarker (cg05575921 methylation) detected both tobacco and cannabis smoke exposure in high school students, distinguishing combusted from non-combusted products.
Adding CBD (200-800 mg/day) to stable SSRI treatment increased citalopram blood levels by ~50% in anxiety patients — a clinically significant drug interaction.
An RCT of 150 autistic participants found a 20:1 CBD:THC extract improved disruptive behavior (49% vs 21%) and social responsiveness but not the primary behavioral outcome measure.
A review found gestational cannabis exposure is associated with impaired placental blood flow, smaller birth size, and potential neurodevelopmental and metabolic risks in children, though definitive evidence remains limited.
A Nature Reviews Neuroscience paper found cannabis exposure during pregnancy and adolescence impairs brain development through epigenetic changes that persist into adulthood and can be passed to future generations.
A children's hospital study found that delayed recognition of cannabis exposure in kids led to twice as many diagnostic tests, four times the avoidable costs, and hospital stays averaging 18 hours versus 4 hours for adolescents.
A Turkish clinic treated 33 autistic children with low-dose CBD-enriched cannabis for a median of 6.5 months. About a third showed improved behavior, and nearly a quarter improved in language, with no significant side effects.
A study of 152 youths found that more severe cannabis use disorder was linked to poorer recognition of sad and fearful facial expressions, independent of conduct disorder. This could represent a pathway through which cannabis increases aggression risk.
An fMRI study found adolescent-onset cannabis users learned new words significantly slower than non-users. Brain imaging revealed disrupted activation in the parahippocampal gyrus, midbrain, and thalamus during learning.
Cannabis vaping doubled among U.S. adults from 2017 to 2019, tripling among 18-24 year olds. While not linked to respiratory symptoms, cannabis vaping was strongly associated with heavy drinking and other high-risk behaviors.
A study of 2,577 mother-child pairs found prenatal cannabis exposure (with tobacco) was linked to higher stress hormone levels in children at age 6, suggesting lasting effects on the developing stress response system.
One in ten licensed Ontario high school students reported driving within an hour of using cannabis. Cannabis dependence was the strongest predictor (OR 12.7), followed by low perceived risk and pro-legalization attitudes.
Eight infants with treatment-resistant West syndrome received CBD-enriched cannabis oil. Four achieved more than 50% seizure reduction, with EEG improvements in seven of eight. Side effects were mild and temporary.
A systematic review of 11 studies found no clear evidence that cannabis compounds cognitive deficits in youth with ADHD, though neuroimaging showed brain differences. The evidence is limited and potentially underpowered.
A Canadian survey of 5,630 emerging adults found both habitual and casual cannabis users had about 1.8 times the odds of traffic violations, with the association strongest among younger users and those not using other drugs.
A study of 703 adolescents found cannabis use linked to specific DNA methylation changes in immune cells. Notably, patterns in T cells and monocytes overlapped with brain tissue findings from psychosis research.
A third of young cannabis-using Ontario drivers reported driving high, with 42% planning to do so again. Past behavior, low moral awareness, and low perceived danger were the strongest predictors of future cannabis-impaired driving.
In 15 young patients with cannabinoid hyperemesis syndrome, 14 had urinary THC metabolite levels above 100 ng/mL. This threshold could help doctors diagnose CHS faster and avoid unnecessary testing.
Tracking 552 young cannabis users from age 19 to 22, psychotic-like experiences did not predict changes in cannabis use, but later age of first use predicted steeper increases.
L-theanine pretreatment in adolescent rats prevented the long-term dopamine dysregulation, molecular changes, and behavioral abnormalities caused by THC exposure.
Michigan saw 426 pediatric cannabis exposures from 2008-2019, doubling every 2.1 years after medical legalization, with young children mostly ingesting products and teens mostly inhaling.
Systematic review of 38 longitudinal studies found that brain development delays, especially in executive functioning, both precede and result from adolescent substance use, with harm tied to frequency and recovery tied to duration.
Rats exposed to THC around birth showed lasting epigenetic changes in dopamine receptor genes and schizophrenia-like behaviors, but adolescent CBD treatment reversed the damage. Similar epigenetic changes were found in human schizophrenia patients.
Analysis of US poison control data from 2017-2019 found rising cannabis exposure reports, with manufactured products and plant materials showing different patient demographics and clinical patterns.
Case series of six children in Italian palliative care found medical cannabis reduced seizure frequency and pain over one year with only mild, transient side effects.
Two studies with 808 and 391 adolescents found that tailored gain-framed messages reduced cannabis use intentions in at-risk teens, especially after first destabilizing their resistance to prevention messaging.
Analysis of 461,706 Florida students found blunt use declined from 2010-2015 then reversed sharply, with notable increases among girls, middle schoolers, and white students through 2020.
Pilot RCT of CBD in eight children with intellectual disability found 100% adherence, no serious side effects, and a preliminary signal of benefit for severe behavioral problems.
Study of 2,051 European teens found endocannabinoid gene interactions (CNR1, MGLL, DAGLA) associated with alcohol use disorder risk, with partial replication in 772 Canadian adolescents.
Blocking CB2 receptors during adolescence in rats impaired Pavlovian reward learning in adulthood but left instrumental conditioning intact, revealing a selective role for CB2 in reward system development.
Survey of 239 young LA cannabis users found CBD-dominant product users were more medically motivated and reported more pain, but also used more illicit drugs, especially psilocybin.
Study of 863 Spanish adolescents found girls had higher mental health-substance use comorbidity, with depression predicting cannabis use disorder and obsessive-compulsive symptoms predicting alcohol use disorder.
Monthly surveys of 761 young adults found marijuana use peaked in April and December, while alcohol peaked in summer, October, and December, with patterns varying by college status.
Study of 1,108 college students found those who mixed prescription stimulants with alcohol or marijuana had the heaviest substance use, most consequences, and used marijuana to alter other drug effects.
Study of 5,792 high schoolers found earlier substance use predicted emotional detachment from parents, which in turn predicted progression to illicit drugs like cocaine and hallucinogens.
Analysis of 71,870 Oregon 11th graders found counties with the most marijuana and alcohol retail outlets had significant increases in adolescent co-use after legalization, mediated by changes in beliefs about availability and risk.
Survey of nearly 3,000 Czech and Slovak university students found tobacco and cannabis use both correlated with alcohol use disorders, with males at higher risk, during early COVID-19.
Interviews with 10 parents revealed families pursued medical cannabis for children with cancer or epilepsy out of desperation, relying on social media and peers rather than healthcare providers for information.
Study of 437 homeless adults found cannabis use before age 15 was linked to substance-induced psychosis while use after 15 was linked to schizophrenia, with corresponding brain differences.
Survey of 401 adults in a California pediatric ER found 14.5% had cannabis at home, but fewer than half stored it locked and hidden, and 45% received no storage guidance.
Adolescent cannabinoid exposure in mice reduced cocaine reward in adulthood and increased a DNA methylation enzyme in the prefrontal cortex, without affecting anxiety or depression.
Analysis of 287,624 US adults with children found cannabis use was 28% higher in recreational legalization states and 12% higher in medical-only states compared to non-legal states.
Mouse model of Tourette syndrome found THC reduced some tic-like behaviors but caused catalepsy, while CBD had no benefit in juveniles and increased head twitching in both age groups.
Study of 599 college students found that perceiving marijuana as risky was linked to lower use, with the association being strongest among younger students.
Twin study of 436 young adults found alcohol misuse was associated with thinner cortex in cognitive control brain regions, reflecting both genetic predisposition and direct exposure. Cannabis showed no such effects.
Systematic review of 12 studies found that nicotine co-use may mask cannabis-related cognitive deficits in young people, while neuroimaging research on co-use effects remains extremely limited.
Study of 367 college students found using alcohol, marijuana, and nicotine together was associated with over 10 times the odds of impaired driving compared to alcohol use alone.
Mice with reduced Reelin protein showed worse social, behavioral, and stress outcomes after adolescent THC exposure than normal mice, suggesting genetic factors influence cannabis vulnerability.
Survey of 1,500 caregivers in Colorado found 11% used marijuana, but 90% of those said their child's pediatrician had never asked about their use.
Analysis of over 1 million high school students across 46 states found no evidence that medical marijuana laws or dispensaries increased adolescent marijuana use from 1991-2015.
Hospital review found a 5-fold increase in pediatric cannabis edible exposures after dispensaries opened, with 16% of 32 children needing respiratory support and 34% hospitalized.
Mouse study found twice-daily adolescent CBD exposure caused no harmful effects on locomotion, anxiety, or spatial memory in adulthood, with a possible learning enhancement.
Prospective study of 35 children with drug-resistant epilepsy found CBD cut abnormal brain discharges nearly in half and improved sleep microstructure in 85% of those with initial sleep abnormalities.
Case series of 5 people with FASD found cannabis (mostly CBD) reduced disruptive behavior scores from 18 to 6, suggesting potential for a condition with very few treatment options.
Case report of a teenager with multiple substance addictions and depression who improved across all domains after switching from antidepressants to CBD, including quitting all illegal drugs.
Study of 247 first-episode psychosis patients found childhood violence and environmental adversity was the strongest predictor of premorbid substance use, more than interpersonal abuse or neglect.
A national longitudinal study of 7,821 US adolescents found that existing substance use, particularly other marijuana products and e-cigarettes, strongly predicted starting to vape marijuana.
A systematic review of 43 longitudinal studies found heavy adolescent alcohol use was associated with widespread brain structure changes, while heavy cannabis use showed more localized effects. Co-use studies generally found alcohol effects were more pronounced.
A survey experiment with 870 young Canadians found that branded cannabis packaging increased appeal while health warnings decreased it. Lifestyle imagery made products seem targeted at younger consumers.
A validation study of 517 adolescents found the S2BI screening tool accurately identified moderate-to-severe cannabis use disorder (90% sensitivity, 89% specificity) but was less reliable for mild cases.
A study of 70 young frequent cannabis users found those with higher trait mindfulness reported fewer cannabis-related problems, though mindfulness did not predict motivation to reduce use.
A 10-year case series found 34 adolescents with cannabis hyperemesis syndrome at one institution, with clinical features matching adult presentations and no antiemetic proving consistently effective.
Mice given daily THC throughout adolescence showed no lasting changes in pain sensitivity, morphine effectiveness, or morphine tolerance when tested as adults, suggesting pain circuits may be resilient to moderate adolescent THC exposure.
A national study of 37,870 high school students found sexual minority girls had higher odds of marijuana use while sexual minority boys had lower odds, revealing important sex-based differences in substance use patterns.
Focus groups in rural South Africa found 11 factors sustaining adolescent marijuana farming, from family tradition and economic necessity to favorable soil conditions and lax law enforcement.
A study of 5,987 young Swiss men found four distinct cannabis use disorder trajectories from ages 20-25, with mental health problems and peer drug use predicting who remained stuck at high severity.
A study of 1.9 million adolescent hospitalizations found cannabis-related admissions increased after legalization, with the steepest rises in recreational states, younger teens, and those without prior mental health diagnoses.
An Australian cohort study spanning 16 years found persistent cannabis, tobacco, and binge drinking from adolescence through young adulthood predicted gambling problems in the early 30s.
Two controlled studies found cannabis reliably increased psychotic-like symptoms, but CBD in the cannabis did not reduce these effects. Adolescents were actually less vulnerable to acute psychotic effects than adults.
A study of 441 adolescents with chronic kidney disease found cigarette smoking worsened proteinuria, but marijuana, alcohol, and e-cigarette use were not associated with kidney disease progression.
A study of 605 young adolescents (mean age 13) found cannabis users scored much higher on hopelessness, depression, and anomalous reality perception, with hopelessness being the strongest unique predictor of use.
Analysis of 1,110 digital cannabis assessments found higher problem scores and polysubstance use predicted driving after cannabis use, with the tool costing under a dollar per use.
Children exposed to marijuana before birth showed more sleep problems, withdrawal symptoms, and aggressive behaviors at age 3.5 compared to non-exposed children, but executive function was not affected.
A 30-day daily diary study found sexual minority young adult smokers had 2-3 times the odds of same-day cigarette-cannabis and triple substance use compared to heterosexual peers.
In a Danish cohort of 1,632 children, early cannabis use by age 15 was the strongest independent predictor of subclinical hypomania at age 16, with a 3-fold increased risk.
Qualitative study of 50 young SGM men finds cannabis used to manage anxiety during sex, substitute for harder drugs, and self-treat depression, with some experiencing adverse effects.
Study of 598 heavy-drinking young adults finds daily cannabis use linked to modestly poorer working memory and more impulsivity, while occasional use showed no deficits.
National analysis of 68 million hospital records finds cannabis use disorder associated with 28-52% higher odds of arrhythmia hospitalization in young adults, with atrial fibrillation most common.
Daily diary study finds simultaneous alcohol-marijuana use increases riding with impaired drivers, while non-simultaneous use of both substances most increases driving after use.
ABCD study of 11,489 children finds prenatal cannabis exposure associated with greater psychopathology, sleep problems, higher BMI, and lower cognition at ages 9-11.
Study of 102 psychosis patients finds earlier cannabis use linked to altered cerebellar brain network structure previously implicated in schizophrenia.
Study of 730 binge-drinking young adults finds daily cannabis use linked to impulsive reward choice and hyperactive ADHD symptoms, with no effects from occasional use.
Systematic review finds benzodiazepines, capsaicin, and haloperidol most effective for pediatric CHS, while traditional antiemetics frequently fail.
ABCD Study data from 11,875 children finds those in legal-cannabis states know more about marijuana but not other drugs, with no link between cannabis knowledge and behavioral problems.
Animal study finds adolescent female rats metabolize vaped THC differently than males, with higher active metabolite levels and greater behavioral sensitivity at lower doses.
Study of 53 young children in NYC found 20.8% had detectable marijuana metabolites in their urine, with rates nearly tripling in housing where smoking was allowed.
Study of 171 young regular cannabis users found sex-specific cognitive effects: males had poorer visual memory while females showed worse attention and executive function, with effect sizes in the medium-to-large range.
Study of 71 hospitalized adolescents found that neither alcohol nor cannabis alone predicted daily self-harm, but using both together on the same day increased self-harm odds by over 30-fold.
Survey of 604 LA young adults found that living near cannabis outlets affected use intentions differently by race/ethnicity, with White young adults near recreational shops showing stronger co-use intentions.
Study of 74 young people found cannabis affected brain volume differently by sex (females had more, males had less), while higher aerobic fitness was linked to greater brain volume overall.
Study of 391 first-time justice-involved youth found emotional dysregulation and positive cannabis expectations predicted cannabis initiation, while self-control was protective.
Randomized trial of 113 at-risk girls found a 12-session trauma-informed intervention (VOICES) significantly reduced cannabis use over 9 months compared to an attention control.
Cardiac arrhythmias among teens hospitalized with cannabis use disorder increased sixfold from 2003 to 2016, with dramatically higher mortality (7.4% vs. 0.1%) and hospital costs when arrhythmia co-occurred.
PK modeling and adverse event data show cannabis and CBD can increase escitalopram and sertraline levels in adolescents, raising the risk of side effects like dizziness and fatigue.
Three-year MRI study found heavy cannabis users showed accelerated cerebellar thickening in regions linked to cognition and motor control, with changes tied to earlier onset of cannabis use.
Study of 301 cannabis-using young adults found those most influenced by legalization attitudes reported the heaviest use and highest problematic cannabis use scores.
Survey of 1,034 college students found higher cannabis use was associated with more hallucinations (independent of depression) and delusional ideation that was more distressing and held with greater conviction.
Canadian study found accidental cannabis ingestions increased 77% in children after legalization, despite no overall change in pediatric ER visit volume when accounting for pre-existing trends.
Analysis of 10,644 adolescent drug users found two-thirds started with marijuana, with a 40% probability of transitioning to other drugs by year 8, lower than the 70-80% rate for those starting with other substances.
Systematic review of 21 studies found adolescent CHS follows adult diagnostic patterns but may be more common in females, with 21% having comorbid mood disorders and cannabis cessation as the only effective treatment.
Danish study of 78 children with severe epilepsy found CBD reduced seizures by 50%+ in 31% at 3 months, with Dravet/Lennox-Gastaut patients responding best (70%). Response declined to 20% at 24 months.
Prospective cohort found marijuana-only use in pregnancy was linked to 66% higher risk of small birth size and 126% higher risk of very small birth size, independent of tobacco exposure.
Analysis of 15,238 US adults found starting cannabis before age 15 was associated with 4.4 times higher odds of lifetime suicide attempt and 3.3 times higher odds of suicidal ideation.
A 27-year-old with no traditional risk factors had a heart attack after cannabis use, showing significant coronary artery narrowing requiring stent placement.
A 24-year-old with no risk factors developed acute myocarditis with reduced heart function and a blood clot after marijuana use, representing a rare but serious cardiac complication.
A survey of 3,805 Italian students found cannabis use at ages 14-15 was associated with a 26-fold higher likelihood of using new psychoactive substances.
Cannabis-related ER visits among Ontario youth rose 4.8-fold from 2003 to 2017, with higher severity and hospital admission rates than non-cannabis visits.
An open-label trial of 31 young people with treatment-resistant anxiety found 12 weeks of add-on CBD (up to 800 mg/day) reduced anxiety severity by 42.6%.
First reported case of a 17-year-old developing superior mesenteric artery syndrome (bowel obstruction) from rapid weight loss caused by cannabinoid hyperemesis syndrome.
An expert panel rated state monopoly as the most effective cannabis policy for reducing youth use, excessive use, and impaired driving, while noting almost no direct evidence exists for most policies.
Children exposed to prenatal cannabis had higher BMI and body fat at age 10, but similar associations with paternal use suggest family lifestyle factors rather than direct fetal effects.
A 20-month study of 59 children with drug-resistant epilepsy found CBD-enriched cannabis reduced seizures by 71% on average, with 12% achieving seizure freedom.
A study of 926 boys identified six substance use trajectories through adolescence, with impulsive sensation-seekers at highest risk for early-onset polysubstance use including marijuana.
Analysis of 328 cannabis marketing violations in Washington State found violations common online and near stores, with community members identifying many targeting minors.
In the ABCD Study, prenatal cannabis exposure was linked to more attention and behavior problems at ages 9-10, but no differences in cognitive performance or brain scans.
Pharmaceutical CBD achieved 2.4x higher blood levels than artisanal CBD in children with epilepsy, with more side effects but a trend toward better seizure control.
Adolescent cannabis vapor exposure produced opposite brain changes in male and female mice: structural changes in females and functional connectivity disruption with cognitive deficits in males.
A study of 2,945 young adults found racial/ethnic minorities experienced worse health, academic, and life satisfaction outcomes at the same levels of alcohol and cannabis use as White peers.
An international expert consensus concluded cannabis is a component cause of psychosis with dose-response and age-response relationships, but alone is neither necessary nor sufficient.
Among 539 university students, impulsiveness explained the link between problematic cannabis use and suicidal behavior, while childhood trauma amplified the cannabis-suicide attempt connection.
A study of 2,995 young adults found cannabis use predicted increasing anxiety over time, while anxious individuals actually reduced their cannabis use, challenging the self-medication hypothesis.
Longitudinal research links prenatal cannabis exposure to lasting effects on behavior, memory, and substance use from childhood through adulthood.
A neuroscience-based school program for older teens reduced binge drinking, cannabis use, MDMA use, and nicotine use at 6 months.
Nationwide data showed young adults with cannabis use disorder had higher rates of hypertensive crisis and worse cardiovascular outcomes during hospitalization.
Review finds early evidence that CBD may safely improve symptoms of autism, intellectual disability, tics, and ADHD in children and adolescents.
Large case-control study found no significant association between maternal cannabis use around pregnancy and autism spectrum disorder in children.
Social networks influenced how often young adults used cannabis, with stronger effects for recreational than medicinal users, but no link to problematic use.
Review of national survey data finds that cannabis legalization has not consistently increased adolescent use, and evidence-based education outperforms fear-based approaches.
Nearly half of young adult cannabis users mixed tobacco with cannabis, and more frequent mixing was associated with greater nicotine dependence.
UK registry data showed 74 ASD patients had significant improvements in quality of life, sleep, and anxiety after starting cannabis-based medicines.
RCT found motivational interviewing reduced alcohol use equally well in Hispanic and non-Hispanic adolescents, with indirect effects on cannabis use through motivation.
All 50 licensed California cannabis outlets checked required age verification, suggesting effective compliance with minimum age laws.
Scoping review found 61-93% of children with autism showed improvement with medicinal cannabis in small studies, with up to 80% reducing other medications.
Meta-analysis of 20 studies found cannabis use was associated with 2.3x risk of suicide attempt, 2.0x suicidal ideation, and 1.7x suicide planning among youth ages 11-21.
Nationally representative Canadian data showed young adults with ADHD had 46% higher odds of cannabis use disorder and 69% higher odds of any substance use disorder.
Birth cohort study found prenatal opioid exposure doubled ADHD risk, with cannabis and alcohol interactions increasing risk further.
Large Spanish survey found low cannabis risk perception and high accessibility mediated the path from demographics to cannabis use among 35,369 adolescents.
CB2 receptors suppress motor tics in adult mice but may generate them in juveniles, with sex differences potentially relevant to Tourette syndrome prevalence.
Pediatric clinicians in Canada support medical cannabis under harm reduction principles but face authorization barriers and want more neurodevelopmental research.
82 children with autism who completed 6 months of CBD-rich cannabis showed significant improvements in social communication on both clinical and parent-reported measures.
Meta-analysis of 45 fMRI studies (2,702 youth) found cannabis users showed altered activation in prefrontal and cingulate regions, varying by sex, severity, and psychiatric comorbidity.
Among 422 pediatric ER patients testing positive for cannabis, 71% presented after legalization. Suicidal ideation was the most common complaint at 43%.
Review argues antidepressants are likely less effective in cannabis-using teens, based on overlapping neurochemical pathways, but no clinical trials have tested this directly.
Standard ASD medications often cause side effects that mimic ASD symptoms. Early evidence suggests CBD-rich cannabis may be effective and better tolerated, but controlled trials are needed.
Among 9,863 US adolescents, racial bullying involvement predicted different substance use patterns by ethnicity, with African American bully-victims more likely to use marijuana.
Analysis of 1,174 young adults found five distinct cannabis use disorder profiles with different patterns of consumption, control, and withdrawal symptoms.
Among 910 young Canadian adults who drive after cannabis use, four distinct profiles emerged, from well-adjusted youth to those with generalized risky behavior and high distress.
Mouse pups exposed to CBD prenatally showed sex-specific disruptions: males gained extra weight and changed vocalizations, while females had impaired motor and discrimination abilities.
Animal studies consistently show prenatal cannabis/THC exposure causes cognitive, emotional, and drug sensitivity changes in offspring, supporting their classification as developmental toxicants.
Among 4,270 French students, ADHD symptoms predicted continued cannabis use after one year but did not drive new cannabis initiation.
Children of caregivers who smoked marijuana had 26% more viral respiratory infections per year compared to unexposed children in a survey of 1,500 families.
Among 1,540 newborns with meconium drug testing, THC-exposed infants weighed 0.16 kg less and had 1.9x the odds of low birth weight.
National data from 2011-2017 found marijuana associated with teen suicidal ideation and attempts at rates comparable to tobacco and alcohol, with a dose-response pattern.
Cannabis use was linked to suicidal ideation in 412 youth aged 13-18, but existing school prevention policies did not weaken this association.
Among 835 high schoolers, buying cannabis from someone or using a medical card at a dispensary predicted continued and more frequent use six months later.
Adding pictures to cannabis warning labels significantly improved health risk recall and perceived effectiveness among 523 at-risk young adults.
CBD reduced seizures by 50%+ in 27% of 41 children with severe epilepsy, but quality of life and adaptive behavior did not improve over six months.
Among 5,738 African American male students, disliking school and believing most peers used marijuana were the strongest predictors of past-year use.
Among 256 pregnant patients, continued cannabis use through delivery was linked to 10% lower birthweight, and mothers with higher childhood trauma scores were more likely to keep using.
In 246 first-episode psychosis patients, 78% had used cannabis, with 94% starting use years before psychotic symptoms. Earlier exposure predicted worse outcomes.
Parental cannabis use was the strongest predictor of teen use among 839 Slovenian students, with mothers' parenting style and specific cannabis rules also playing key roles.
Edible gummies were seen as healthier and more appealing than other cannabis forms. Health claims on packages boosted positive feelings, while health warnings had little effect.
Young adults who newly adopted an LGBQ+ identity had 2.9x the risk of starting cannabis use, suggesting identity transition is a vulnerable period.
Following 701 people from age 10 to 22, high social anxiety trajectories predicted adult cannabis use (but not alcohol) along with dramatically elevated mental health disorder risk.
Cannabis users showed worse verbal memory than controls, but adolescent users (16-17) were not more impaired than adult users (26-29), challenging the adolescent vulnerability hypothesis.
Adolescent THC exposure caused lasting, sex-specific hippocampal damage in rodents, with females more severely affected through disrupted estrogen-endocannabinoid signaling.
Daily THC during adolescence disrupted brain immune cell (microglia) function in mice through young adulthood, impairing responses to infection and stress. Effects were adolescent-specific and eventually resolved.
The largest neuroimaging review of adolescent cannabis use (90 studies, 9,441 participants) found evidence of altered brain structure and function in frontoparietal, frontolimbic, frontostriatal, and cerebellar regions.
Review described how edible cannabis products pose unique pediatric risks due to food-like appearance, copycat packaging, lack of smell, and delayed onset that promotes overconsumption.
A three-year follow-up of 1,689 adolescents found that even low-level alcohol use in the emergency department predicted nearly double the odds of developing cannabis use disorder.
Review found the best evidence for treating pediatric cannabinoid hyperemesis syndrome is IV rehydration plus haloperidol 0.05 mg/kg, with cannabis cessation as the only long-term cure.
Longitudinal brain imaging of 724 adolescents found combined alcohol and cannabis use accelerated gray matter decline in five brain regions, with neither substance alone producing the same effect.
A 9-year-old with nonverbal autism showed reduced violent outbursts, better sleep, and improved social interactions after starting full-spectrum CBD oil with low-dose THC.
Study of 68,037 Canadian students found school disciplinary approaches to cannabis did not directly affect use, but supportive schools fostered perceptions that were linked to lower cannabis use.
Review found published cases supporting cannabis safety for chemotherapy nausea in children and preclinical evidence of anti-cancer effects on pediatric tumors, but called for more research.
In South African cannabis-growing communities, non-using teens cited academic focus, religious beliefs, family dignity, and fear of legal consequences as reasons for abstaining from cannabis.
First study showing adolescent mice voluntarily self-administered synthetic cannabinoid JWH-018, leading to lasting compulsive behaviors and brain neuroinflammation in adulthood.
Children exposed to cannabis in utero had 1 kg more fat mass, 2.6% higher body fat, and 5.6 mg/dL higher blood sugar by age 5 compared to unexposed children.
Critical review of 69 articles confirmed CBD is effective for Lennox-Gastaut, Dravet, and tuberous sclerosis complex seizures in children, with a good safety profile despite frequent mild side effects.
Analysis of 2,660 social media posts from cannabis companies found 35% contained prohibited promotions and fewer than half included required safety warnings, with youth-appealing content common.
Review found cannabis is a risk factor for violence in early-phase psychosis, with impulsivity as a potential mediating mechanism linked to cannabis effects on frontal brain regions.
RCT found adolescents (18-20) showed cognitive impairments and brain wave changes from THC that adults (30-40) did not, despite both groups feeling equally intoxicated.
Three adolescents with cannabinoid hyperemesis syndrome developed recurrent dangerously low phosphorus levels, highlighting the need for close electrolyte monitoring in young CHS patients.
A web-based school prevention program reduced alcohol uptake by 38-51% in over 6,000 Australian students but did not significantly affect cannabis use at 12-month follow-up.
Among cannabis-using Massachusetts youth, use of diverted medical cannabis rose from 15% to 44% between 2013 and 2016, with higher rates of cannabis-impaired driving among diverted users.
Review found that cocaine, amphetamines, alcohol, and marijuana all contribute to premature cardiovascular disease in young and middle-aged adults, representing a growing public health problem.
Survey of 122 Canadian pediatric oncologists found 86% saw cannabis potential for nausea, 72% for pain, and 67% for appetite in children with cancer. Nearly all wanted more research.
Causal modeling of 637 IMAGEN study adolescents found a directional relationship from cannabis use to accelerated prefrontal cortical thinning, consistent with cannabis affecting brain development.
Analysis of 3.3 million California students found marijuana legalization increased alcohol-cannabis co-use by 6% overall and 58% among past-month drinkers.
Among 3,205 substance-naive children, higher genetic risk for lifetime cannabis use was associated with better cognitive scores, suggesting shared genetic overlap with traits like curiosity rather than a cannabis benefit.
RCT of 1,473 Swiss students found a 22-week mobile phone life-skills program reduced cannabis use by 45% and tobacco by 33% at 18 months, with no effect on alcohol.
Review found CBD shows biological plausibility and early promise for ASD symptoms through the endocannabinoid system, but clinical evidence is limited and the authors caution against premature use.
Review explained how the developing endocannabinoid system makes adolescent brains uniquely sensitive to THC, particularly through disruption of still-maturing dopamine circuits linked to psychosis and addiction.
Nationwide Swiss data showed sharp increases in cannabis-related psychiatric hospitalizations from 1998-2020, concentrated in the 15-44 age range.
Among 1,424 adolescents, anxiety/depression predicted cannabis use only in girls with high ADHD hyperactivity-impulsivity, highlighting a specific risk profile for targeted intervention.
Modeling predicted THC could increase methylphenidate levels by 34% and high-dose CBD by up to 55% through CES1 enzyme inhibition, a previously unreported drug interaction mechanism.
Adding a self-regulation-focused Grit program to residential substance treatment produced larger reductions in cannabis and methamphetamine use in young adults, sustained at 12 months.
Analysis of 204,730 students found Uruguay's 2013 cannabis legalization was not associated with sustained increases in youth cannabis use, risky use, or frequent use.
Multilevel school health program across 237 US schools reduced current marijuana use by 23% among 64,838 students, along with reductions in sexual risk and violence.
US cannabis ER visits rose 12% annually from 2006-2014 and continued increasing after 2016. The Midwest had the largest regional surge (36.8%), with notable increases among children and females.
Longitudinal study of 1,084 young adults found 27% increased marijuana use during early COVID-19. Childhood adversity predicted increases among those with low resilience.
Parents secretly administered a CBD extract to their 4-year-old with brain inflammation, not telling doctors because they assumed the legal product was safe, highlighting risks of unregulated self-prescribing.
Analysis of 881 TikTok cannabis videos found 54% portrayed use positively with 417 million views. 72% used humor. None were age-restricted despite massive youth exposure.
Three-year study of 461 first-episode psychosis patients found those who quit cannabis showed the most attention recovery, reaching scores closest to healthy controls.
Case report of a young adult with cannabis use, COVID history, and other complicating factors who developed severe psychosis but achieved complete recovery.
Study of 1,023 young adults found perceived parental approval of marijuana and heavy drinking was the strongest predictor of simultaneous alcohol-marijuana use.
Largest fMRI study of cannabis and reward processing (125 participants) found no differences between users and non-users in reward anticipation, with adolescents showing no extra vulnerability.
Phase III interim analysis of 59 children with autism found CBD-rich cannabis oil (20:1 CBD:THC) produced no clinically significant blood chemistry changes over 3 months.
ABCD study of ~12,000 children found 1.1% reported cannabis use by ages 12-13, with externalizing behaviors and parental drug problems predicting earlier substance initiation.
Study of 79 young people found cannabis withdrawal symptoms peaked in the first week of monitored abstinence then declined, with mood and sleep most affected.
Analysis of 256 cannabis edibles packages found widespread youth-appealing content including candy knockoffs and cartoon characters, with less-regulated states having the most.
Quebec cohort study of 2,408 children found no significant association between in-utero cannabis exposure and ADHD risk after adjusting for confounders.
Pilot trial of 97 college students found mobile phone intervention with personalized feedback and text messaging reduced driving after cannabis use over 3 months.
American Heart Association scientific statement concluded marijuana may adversely affect brain health through cognitive impairment and increased stroke risk, especially during neurodevelopment.
Retrospective study of 114 children with drug-resistant epilepsy found 73% improved with CBD-enriched oil, with 59% achieving over 50% seizure reduction over at least one year.
Focus groups with 57 Canadian young adults found they wanted cannabis edibles packaging focused on safe use (standardized dosing, child safety) rather than consumption deterrence.
Spanish expanded access program of 102 patients found CBD reduced seizures by 48%, with 45% achieving over 50% reduction at 6 months in highly refractory epilepsy.
Study of 1,099 people with psychotic disorders found those with atypical psychosis had early cannabis use rates (17.5%) closer to schizophrenia (11.5%) than psychotic bipolar disorder (5.3%).
Small study of 18 adolescents found chronic cannabis use linked to DNA methylation changes at six sites that statistically mediated lower verbal memory scores.
Study of 451 Latinx college students found attachment style, marianismo beliefs, and bicultural self-efficacy shaped the link between childhood adversity and substance use among women.
Study of 2,293 adolescents found parent disapproval directly reduced cannabis use while peer disapproval worked through changing risk perception, with similar patterns in legalized and non-legalized states.
NYC survey found 30.7% of families experienced marijuana smoke incursions during the pandemic, with families in subsidized housing facing nearly 7 times the odds and their children having 3 times the asthma rate.
Scoping review of animal studies found cannabinoid exposure during brain development (prenatal, adolescent) caused lasting cognitive harm, while exposure in old age showed potential cognitive benefits.
Longitudinal study of 1,465 young people found cannabis use and suicidal ideation were reciprocally linked from ages 15-20, suggesting they may reinforce each other over time.
Mouse study found adolescent THC exposure changed brain gene networks differently by sex, with four key driver genes also linked to human cannabis use disorder vulnerability.
Rats exposed to combined alcohol, cannabinoid, and nicotine during adolescence showed lasting learning deficits in adulthood, with females affected earlier than males.
Adolescent rats given CBD-enriched cannabis extract showed no behavioral changes but had significant hippocampal synaptic protein alterations, suggesting hidden molecular effects during brain development.
10-year study of 704 people found adolescent cannabis initiation caused prefrontal cortex thinning linked to later drug use, while young adult initiation affected temporal areas linked to psychotic symptoms.
Swedish conscript study found schizophrenia patients with adolescent cannabis history had earlier onset, more hospitalizations, and more hospital days than those without.
Study found clinical psychosis risk youth had elevated cannabis, alcohol, and tobacco use, while genetically at-risk youth (22qDel) had lower rates, with social and cognitive factors explaining the difference.
Review found recreational cannabis legalization mostly did not increase youth use, but accidental pediatric edible ingestion rose significantly, along with some increases in adolescent alcohol and vaping.
Study of 168,589 pregnancies found children of prenatal cannabis users were 43% more likely to miss their 12-month check-up, with 36% missing two or more visits by age 3.
New Zealand survey of 11,405 teens found regular cannabis use stable despite declining lifetime use, with 24% of users vaping and highest rates among Maori, LGBTQ+, and disadvantaged youth.
California study of 34,544 births with maternal CUD found 40% higher infant mortality in the first year (1.0% vs 0.4%), driven by perinatal conditions and sudden unexpected infant death.
Qualitative study found young people ride with cannabis-impaired drivers during routine daytime activities, citing trust and familiarity, with safety concerns developing only in young adulthood.
RCT found adolescents who quit cannabis experienced trouble falling asleep during the first week, but sleep returned to normal by week two and stayed there through week four.
Study of 74,501 Canadian students found those in areas with greater income inequality were 25% more likely to use cannabis daily, independent of individual-level factors.
Animal study found the endocannabinoid system in the prefrontal cortex develops on different timelines in male and female rats, with females maturing earlier.
French hospital data from 2010-2019 found cannabis use during pregnancy associated with prematurity and small-for-gestational-age births compared to tobacco-only and non-using controls.
CBD reversed social behavior deficits, abnormal stress responses, and brain plasticity changes caused by adolescent binge drinking and social stress in a rat model.
Real-time tracking of 62 psychiatrically hospitalized teens found cannabis use boosted positive mood and reduced anger, with stronger effects in youth with PTSD or anxiety disorders.
Study of 42,149 Canadian students found school-based substance prevention programs showed no overall benefit and some approaches increased cannabis use in low-use schools.
Systematic review of 19 studies (1,927 pediatric cancer patients) found cannabinoids commonly used for chemotherapy nausea with no serious adverse events, but dosing evidence remains insufficient.
Pilot RCT found a personalized feedback program targeting sensation seeking, impulsivity, and other risk traits significantly reduced cannabis use in college freshmen.
Prospective study of 138 pediatric cannabis intoxications found 38% required ICU care, with young age and polysubstance use as the strongest predictors of severe outcomes.
Survey of 5,428 Oklahoma adults found 75% reported cannabis marketing exposure, which was associated with more positive attitudes and greater cannabis use.
Eye-tracking study of 72 young adults found youth-appealing cannabis edible packaging increased product appeal and reduced attention to warning labels.
National Jamaican survey found nearly 20% of adolescents used marijuana recently, with loneliness, suicidal ideation, and parental smoking among key correlates.
Vienna study found only 32 severely ill children received THC over 3 years, with significant gaps in prescribing documentation despite the high-stakes clinical context.
Multi-site study of 1,185 people found cannabis and childhood trauma interacted to predict earlier psychosis onset, with hippocampal volume as a biological mediator.
Delta-8 THC boomed after the 2018 Farm Bill accidentally legalized it, but this scoping review found almost no human safety data behind the millions of products being sold.
A study of nearly 10 million people found ER visits for substance-induced psychosis carried a 163-fold increased risk of later schizophrenia, with cannabis showing the highest transition risk of any substance.
Ontario data showed no increase in cannabis psychosis ER visits after initial legalization, but a 30% jump after retail and product expansion, driven by youth aged 19-24.
Cannabis-exposed pregnancies showed head circumference deficits starting in the second trimester, reaching more than 14 percentile points by birth, after controlling for other substance use.
Children prenatally exposed to both a natural disaster and maternal cannabis use had synergistically elevated psychiatric risk, with a 31-fold increase in behavioral disorders.
Narrative review proposes adolescent CUD develops through feedback loops between drug characteristics, individual mindset, and environmental setting.
Only 9 RCTs exist for CBD across all neurodevelopmental disorders, with inconsistent results.
Prenatal cannabinoid exposure disrupted breathing regulation in rat offspring sex-specifically: males had altered CO2/O2 responses while females had increased apnea with reduced brainstem serotonin neurons.
Scoping review found no proven intervention for reducing cannabis use in young adults with psychosis, though MI, CBT, and family training show minimal evidence.
Machine learning found medical cannabis shifted salivary biomarkers in autistic children toward typical levels, with THC and CBD producing distinct metabolic signatures.
US ecological study found daily cannabis use and first-trimester exposure were statistically associated with autism rates in 40 million children, with exponential dose-response patterns.
CDC data showed cannabis ED visits among youth increased during the COVID pandemic, with the steepest rises in children under 10 and a notable shift to higher rates among adolescent girls.
Among 352 Colombian adolescents, cannabis and tranquilizer use were independently linked to suicidal behavior alongside depression, aggression, and borderline traits.
Review found adolescent cannabis use disrupts critical brain development, with concern that new high-potency products and delivery devices amplify the risk.
Review highlighted that combined alcohol-cannabis use during pregnancy is increasingly common but virtually unstudied, despite evidence that co-use amplifies effects.
National survey found 6.3% of US drivers aged 16-20 reported driving after cannabis use, more than double the alcohol DUI rate of 2.6%.
Nationwide data showed heart attacks among young cannabis users nearly tripled from 2007 to 2018, with the steepest increase among Black Americans.
Prenatal cannabis smoke exposure in rats altered litter sex ratio, increased adult offspring anxiety, changed amygdala genes, but improved some cognitive tasks.
Adolescent THC edible experience in rats enhanced alcohol's stimulant effects and altered frontal cortex endocannabinoid levels during alcohol withdrawal.
Review found adolescent cannabis use causes lasting cognitive changes through epigenetic modifications and synaptic disruptions, worsened by high-potency products and early initiation.
Review found converging evidence that frequent adolescent cannabis use reduces cognition, but debate continues about whether effects persist after quitting and whether brain imaging findings replicate.
Adding EMA to counseling increased mindful awareness in young cannabis users, and higher mindfulness was linked to lower cannabis desire and negative affect.
Controlled fMRI study found THC blunted reward-related brain activity in adults but not adolescents. Adding CBD partially offset the effect in adults.
ABCD Study analysis of ~10,000 children found sleep protects against behavior problems, but prenatal cannabis exposure significantly weakened this protective effect.
Two case reports show adolescent vaping of nicotine and marijuana during COVID linked to social stressors and mental health symptoms, highlighting need for holistic treatment.
National survey of 68,000+ US teens found nondisordered cannabis use (10.2%) associated with doubled odds of depression, suicidal ideation, and academic problems vs. non-use.
Prospective cohort found late prenatal cannabis exposure associated with higher language scores at 12 months in 69 exposed vs. 138 unexposed infants.
Meta-analysis of 6 RCTs confirms CBD (Epidiolex) significantly reduces seizures in Dravet, Lennox-Gastaut, and tuberous sclerosis complex, with notable side effects.
2-year longitudinal study of 401 Hispanic adolescents found poor explicit-risk decision-making predicted escalating cannabis use and related problems.
Systematic review of 28 studies (523,107 patients) found no significant pooled associations between prenatal cannabis exposure and child cognitive or academic outcomes.
Chart review of 110 teens found aripiprazole associated with shorter hospital stays (5.8 vs. 9.7 days) than risperidone for cannabis-related psychosis.
Study of 323 cannabis use disorder patients found most had pre-existing adverse childhood experiences, social-emotional impairments, or neurodevelopmental conditions.
Rome police seizures show hashish THC nearly doubled from 13.7% to 27.1% in seven years, with some samples exceeding 40% — and young males are the primary users.
Cross-sectional study finds cannabis use linked to adverse psychosocial functioning among North American college students, extending adolescent findings to ages 18-22.
ABCD Study found limited concordance between teen self-reported substance use and hair toxicology, with hair testing detecting use teens denied.
ABCD Study of 5,580 youth found secondhand cannabis and tobacco smoke exposure associated with lower cognitive scores, even without direct use.
Survey found almost no US film incentive programs restrict cannabis or tobacco depictions, despite evidence that media exposure influences youth substance initiation.
Review finds cannabis increases psychosis risk, worsens outcomes in vulnerable youth, and recommends integrated treatment approaches for co-occurring use and psychotic symptoms.
Population study of 150,634 California teens found e-cigarettes, cigarettes, and cannabis each independently associated with asthma, with additive combined effects.
Animal study found THC and CBD had distinct effects on BDNF and TrkB expression in the adolescent hippocampus, suggesting different impacts on brain development.
Longitudinal study found marijuana and e-cigarette use among young adults who had pediatric bariatric surgery, raising post-surgical substance use concerns.
Review of 10 clinical trials confirms CBD reduces seizures in pediatric Dravet syndrome with manageable side effects and notable clobazam interactions.
Chicago parent survey found knowledge gaps about cannabis laws and health effects, with many parents not discussing cannabis with their adolescents.
ABCD Study data linked prenatal cannabis exposure to blunted brain reward responses and psychotic-like experiences in youth, suggesting dopamine-related circuitry disruption.
Meta-analysis linked prenatal cannabis to 30% higher ASD risk. A large cohort study found cannabis use disorder before or during pregnancy associated with 3x higher ASD risk.
Massachusetts data showed a 60% increase in pediatric cannabis ER visits and 126% increase in hospitalizations after recreational legalization, with youngest children most affected.
Four-year study of 3,085 college-age adults found depressive symptoms predicted cannabis vaping initiation, with rates doubling from 2017 to 2019.
Study of nearly 120,000 pregnancies found no link between early-pregnancy cannabis use and child developmental delays through age 5.5, at any frequency of use.
Study of nearly 179,000 pregnancies found no association between early-pregnancy cannabis use and child autism after adjusting for maternal factors, contrasting earlier studies.
US children's hospital data showed substance-related visits grew 48% from 2016-2021, with cannabis dominating (52% of visits, 82% growth) and Hispanic youth seeing the largest increase.
Review of 24 studies found youth cannabis use linked to depression, psychosis, suicide, and cognitive decline in Australia and the US, with effects worsening with heavier use.
ABCD Study of 9,000+ adolescents linked prenatal cannabis exposure to frontal/parietal brain differences, with some changes partially explaining the pathway to ADHD.
Meta-analysis of 534,445 participants found prenatal cannabis slightly increased ADHD risk (13%) and offspring cannabis use (20%) but showed no link to autism, psychosis, anxiety, or depression.
Study of 80 adolescents found half used synthetic marijuana alongside natural, primarily to save money and avoid drug tests, with dual users showing more behavioral problems.
Study found youth with more sleep trouble used more cannabis overall, but on specific bad-sleep nights, they were actually less likely to use the next day.
Survey of 2,530 California teens found two-thirds noticed substance ads, with cannabis advertising exposure associated with doubled odds of expecting to use marijuana among never-users.
A brief two-session personality-targeted school program reduced cannabis-related harms by 22% over 7 years in high-risk Australian adolescents, though it did not significantly reduce cannabis use itself.
JAMA Pediatrics meta-analysis of 23 RCTs with 3,612 young patients found medical cannabinoids associated with 3x more treatment withdrawals, 5.7x higher liver enzyme elevations, and 2.3x more drowsiness versus placebo.
Oregon middle school substance discipline referrals increased 30% after marijuana legalization compared to control states, with dispensary proximity amplifying the effect. High schools showed no significant change.
Among 945 depressed/suicidal youth, 12.7% showed high use of all substances and had the most ADHD, substance use disorders, and suicidality, while 23.8% showed moderate alcohol/nicotine/cannabis use.
Longitudinal study of 381 people found weekly childhood cannabis use and depression independently accelerated DNA methylation aging from adolescence to adulthood, with combined effects equivalent to 3-4 extra years of biological aging.
RCT of 220 non-treatment-seeking youth found 4 weeks of incentivized abstinence reduced cannabis use and shifted 68% toward reduction goals, with benefits persisting 4 weeks after incentives ended, especially in those without CUD.
Meta-analysis of 19 RCTs found digital interventions reduced young adult cannabis use by nearly 7 fewer days per month at 3-month follow-up, with personalized feedback being the most common active ingredient across programs.
In adolescent rats, THC exposure caused lasting anxiety and depression-like behaviors linked to brain changes in the nucleus accumbens. The antioxidant NAC prevented all of these effects.
A cluster RCT of 950 Australian students found an online harm reduction program slowed uptake of binge drinking, cocaine, and prescription drug misuse over 12 months, but had no significant effect on cannabis use.
In a nationally representative study of 5,585 US youths, concurrent tobacco and cannabis use was linked to nearly double the odds of behavioral problems compared to using either substance alone.
A longitudinal study of 850 teens found that affiliation with delinquent peers partially mediated the link between cannabis use and aggression, suggesting social context matters as much as substance use itself.
In a prospective study of 545 young women of color, frequent cannabis use (20+ times monthly) predicted increased depression, delinquency, and school suspension over 6-12 months.
Controlled fMRI study found vaporized cannabis disrupted five major brain networks equally in teens and adults, and CBD co-administration did not reduce THC effects, challenging assumptions about CBD safety.
In King County, Washington, cannabis use declined among students from 2008-2021, but female students surpassed male students in current use prevalence for the first time in 2021.
ABCD Study analysis of 10,395 children found no evidence that state recreational cannabis laws affected children's perception of cannabis risk over a 3-year period.
Survey of 69,621 Canadian students found nearly half of dual alcohol-cannabis users reported impaired driving or riding exposure, with 9.5 times higher odds than alcohol-only users.
Norwegian 13-year longitudinal study of 1,988 youth found within-person cannabis use increases linked to anxiety, depression (males), and suicidal ideation (3.4x in males, 2.5x in females).
An RCT found that an app-based parenting program was especially effective at reducing anxiety in parents who started using cannabis regularly during adolescence.
A crossover RCT with 48 cannabis users found THC eliminated the tendency to look away from cannabis images. CBD did not change this effect, and adolescents responded similarly to adults.
Data from 323,896 US college students (2009-2019) showed the link between cannabis use and mental health problems grew substantially stronger over the decade.
MRI study of 223 teens and young adults found cannabis and nicotine each thinned the frontal cortex, but using both together partially offset the nicotine-related thinning effect.
Annual Washington State surveys found young adult cannabis-impaired driving stayed at about 12.5% through the COVID pandemic, with no significant change from pre-pandemic trends.
A study of 1,941 Washington State young adults found peer approval of driving after combined alcohol and cannabis use predicted impaired driving behavior more than perceived prevalence.
Five years after Washington opened cannabis retail stores, alcohol DUI decreased and cannabis DUI held steady overall (11%) while dropping among cannabis users.
A matched case-control study found prenatal cannabis exposure was linked to lower cognitive and motor scores at age three, with the most severe delays in language development among boys.
A longitudinal study of 247 dyads found prenatal tobacco-cannabis co-exposure blunted emotional reactivity in toddler boys, while continued postnatal cannabis exposure heightened reactivity.
A 12-month study of 204 Oregon teens found that perceiving more peer cannabis use and having less ability to resist peer pressure predicted increasing hazardous cannabis use.
Interviews with 88 Ontario youth, parents, and providers found widespread concern about cannabis harms alongside normalization, with structural barriers hampering harm reduction efforts.
A study of 4,448 Texas college students found four cannabis-tobacco co-use patterns that remained largely stable over three years, with 42% of students using at least one substance.
A national birth cohort study found later bedtimes and shorter sleep in childhood predicted higher odds of trying marijuana by age 15.
Analysis of 1,789 urban adolescents identified five distinct substance use patterns, with mental health and perceived drug access differentiating higher from lower risk groups.
An RCT of 84 adolescent inpatients with cannabis use disorder found mindfulness therapy added to standard care did not improve cannabis outcomes at 6 months, though standard care was effective.
A 21-day diary study of 237 college students found co-use of alcohol and cannabis was more pleasurable than cannabis alone, but alcohol appeared to drive the pleasure effect.
Survey of nearly 24,000 students found most teen e-cigarette users wanted to quit or cut back, but fewer were motivated to change their cannabis use.
An 8-year study found that light cannabis use in late adolescence was associated with conduct problems but not with cognitive decline or changes in reward-related brain activity.
A study found that nearly one-third of Illinois cannabis dispensary social media posts violated advertising regulations in the first year of legal sales.
College drinkers with ADHD had worse sleep and more alcohol-related consequences, but ADHD did not increase cannabis-related negative outcomes.
A 7-year-old experienced cardiac arrest 7 hours after eating THC gummies, the first pediatric case of THC-induced asystole.
A systematic review found CBT shows promise for adolescent CUD, with shorter courses and parental involvement most promising.
CBD-dominant cannabis extract improved communication, attention, and behavior while reducing aggression in 30 children with moderate-severe autism.
Most tobacco-cannabis co-users tried tobacco first, with nicotine e-cigarettes the most common initial product, especially among teens.
A study of 11,363 Ontario youth found cannabis use was associated with 11-fold psychosis risk during adolescence but no significant risk during young adulthood.
Content analysis finds most US states with legal cannabis have weak warning labels averaging 57 words, with almost none requiring mental health or psychosis risk warnings.
Randomized trial found that A-CRA therapy helped Iranian teen boys with cannabis use disorder achieve higher abstinence and better family relationships than standard treatment.
Legalization strengthened the link between seeing cannabis as low-risk and using it, but broke the link between use and seeking treatment, leading to declining teen treatment admissions.
Two adolescent CHS cases and a literature review reveal dangerous QTc prolongation risks when haloperidol treatment compounds the cardiac effects of cannabis and electrolyte imbalances from vomiting.
In nearly 10,000 children, brain structural differences including thinner prefrontal cortex and larger overall brain volume preceded and predicted substance use initiation before age 15.
Mississippi YRBS data shows cannabis use among high schoolers clusters with vaping, tobacco, alcohol, and sexual behaviors, with no gender or racial differences in cannabis use rates.
Review of 59 studies finds prenatal cannabis exposure consistently predicts low birth weight followed by rapid weight gain, increased body fat, and higher glucose in childhood.
In a rat schizophrenia vulnerability model, adolescent THC impaired social behavior but did not worsen or interact with prenatal immune activation-induced cognitive deficits.
Adults prenatally exposed to cocaine started cannabis younger, and this earlier onset mediated the path to higher anxiety and more severe cannabis use in adulthood.
A web-based tool for teen drivers addressing cannabis and alcohol impaired driving showed strong acceptability in early testing, with nearly all participants finding it helpful.
A translational study connecting mouse neuroscience with human brain imaging identified specific genes and cell types that may explain cannabis-related cortical thinning in adolescents.
In 172 Black mother-child pairs, prenatal cannabis did not predict autism behaviors. Stress was the risk factor.
Largest study (11,570 children, 34 cohorts) found no prenatal cannabis-autism link after controlling for tobacco.
Irish survey of 4,400+ teens found peer cannabis use was the strongest risk factor (10x odds).
Preschool executive control problems predicted harsher parenting in adolescence, which in turn predicted higher teen e-cigarette use, though not cannabis or alcohol use.
First study using vaporized prenatal THC found decreased attention in rat offspring, with low doses producing more pronounced effects than high doses.
Prenatal tobacco-cannabis co-exposure affected children's emotional regulation primarily through ongoing maternal stress and substance use, not direct prenatal effects. Sensitive parenting buffered risks.
Neglected adolescents were more likely to develop impulsive decision-making that led to increased cannabis use over time, identifying a specific prevention target.
Higher mindfulness skills in Argentine college students were linked to less cannabis use through reduced emotional distress and lower coping-based use motives.
Small exploratory study found chronic cannabis-using teens had lower B cell proportions, suggesting possible immune effects that need confirmation in larger studies.
Daily cannabis use at age 24 was linked to elevated suPAR, a novel chronic inflammation marker, while less frequent use and traditional inflammatory markers showed no association.
Systematic review found THC increases key astrocyte (brain support cell) markers, with effects varying by developmental stage and sex across 12 studies.
Cannabis-related ER visits by youth nearly doubled from 2018 to 2023 across six urban hospitals, with notable increases among younger teens and female patients.
Purified CBD as add-on therapy achieved >50% spasm reduction in 68% of 28 infants with treatment-resistant epileptic spasms, with particularly strong responses in Down syndrome patients.
Systematic review found only 18 studies (just 1 RCT) on cannabinoids for child/adolescent neuropsychiatric disorders across 4,466 screened.
Nationally representative longitudinal study found past-year marijuana use associated with 30% lower college completion at four-year schools, with dose-response effects.
Cannabis use disorder worsens PTSD through psychological inflexibility — rigid, avoidant thinking that prevents trauma processing — a mechanism that's treatable with targeted therapy.
Systematic review of 19 studies found youth cannabis exposure linked to effects from transient mood changes to permanent cognitive alterations, though most evidence comes from animal studies.
California survey of ~159,000 students found secondhand marijuana smoke exposure nearly as common as tobacco secondhand smoke, with higher rates among students with asthma.
Pediatric study found CHS patients were older, had higher blood pressure, lower potassium, and positive drug screens compared to CVS patients, while imaging was rarely helpful for either condition.
Case series of 9 adolescents found cannabinoid hyperemesis syndrome co-occurring with superior mesenteric artery syndrome, likely linked through CHS-related weight loss.
ABCD study of 10,092 early adolescents found multiple dimensions of gender diversity associated with higher odds of cannabis experimentation at ages 12-13.
Evidence summary found prenatal cannabis exposure associated with attention problems, hyperactivity, memory challenges, and diminished academic performance in children, though confounders limit causal conclusions.
Study of 133 children found prenatal tobacco exposure increased impulsive responding, but adding cannabis did not worsen effects. Unexpectedly, co-exposed children scored higher on short-term memory.
Pilot study of telehealth counseling plus smartphone-based interventions for young cannabis users showed 100% engagement and 27% reduction in use days at 2-month follow-up.
Randomized controlled trial found CBD-rich cannabis extract significantly improved social interaction, anxiety, and agitation in 60 children with autism over 12 weeks, with minimal side effects.
Analysis of 5,194 young adults found 1.1% had both cannabis use and social anxiety, strongly associated with other psychiatric disorders including panic disorder (OR up to 19.05).
Meta-analysis of 57 studies found prenatal cannabis exposure increased risks of preterm birth (68%), low birth weight (160%), and NICU admission (151%), with limited cognitive effects beyond attention problems.
National survey of 8,033 young adults found cannabis vaping associated with wheezing and cough at rates comparable to nicotine vaping — dual vaping had the worst respiratory symptoms.
Australian study of 222,534 mother-child pairs found maternal cannabis use disorder associated with three-fold higher autism risk in offspring, with stronger effects in males.
Meta-analysis of 36 studies and 18 million births found prenatal cannabis exposure associated with 2-3x higher risks of cardiovascular, GI, CNS, and genitourinary birth defects.
Meta-analysis of 14 studies found prenatal cannabis exposure associated with higher ADHD symptom scores and a 30% increased risk of autism, involving over 200,000 participants.
Prenatal CBD oil (THC-free) prevented autism-like behaviors in all three core symptom domains in male rat offspring from a neuroinflammation-based ASD model.
Study of 470 psychiatrically hospitalized adolescents found cannabis vaping as the primary use method associated with 2.4x higher odds of recent suicide attempt.
French ER study found nearly 1 in 4 young visitors (16-25) were using cannabis, with strong associations to unemployment, sexual abuse history, and alcohol problems.
First study of drug use in Burkina Faso prisons found cannabis was the most common drug (71% of users), with one-third of in-prison users starting drug use while incarcerated.
Review of the past decade of research explains how cannabis triggers psychosis by disrupting the endocannabinoid system during adolescent brain development, affecting synaptic pruning and neurotransmitter signaling.
Multicenter Israeli study found purified CBD reduced seizures in 92% of 139 children with drug-resistant epilepsy, with 41% achieving >50% reduction and prior CBD oil response predicting success.
NIDA leaders identify critical research gaps: effects of high-THC cannabis during brain development, therapeutic endocannabinoid system manipulation, and CUD treatment strategies.
Study of 140 adults in addiction treatment found those with ADHD started substance use younger and had higher rates of cannabis, alcohol, and methamphetamine use.
RCT of 1,489 university students found the Minder app significantly reduced anxiety, depression, and cannabis use frequency over 30 days, with 77% engagement.
Systematic review found only 5 RCTs on integrated treatment for psychiatric disorders in cannabis-using youth, revealing a critical gap for depression, bipolar, anxiety, and PTSD.
Study of 225 young adults found greater cannabis use linked to small reductions in emotional processing speed and working memory, with modest age-of-onset effects but no sex differences.
Hair testing for THC metabolites in 13- to 14-year-olds revealed cognitive deficits in memory, verbal ability, and inhibitory control that self-reported cannabis use alone did not capture.
Among 12- to 15-year-olds in the ABCD Study, cannabis use was linked to more depression symptoms, with the strongest association in teens who also had smaller amygdala volumes.
Lab analysis of vaping products from 16 California high schools found 90% of disposable vape pens contained THC or CBD, and some nicotine labels were inaccurate.
Large pandemic-era cohort found prenatal cannabis exposure linked to a borderline increase in communication delays at 12 months that did not survive statistical correction, with no effects on birth outcomes or other developmental domains.
Cannabis use was the only substance independently linked to lower grades, truancy, and detention in teens, with significantly stronger associations among adolescents with chronic illness.
Brain connectivity patterns linked to poor sustained attention at age 14 predicted increases in cannabis and cigarette use through age 23, suggesting attention deficits precede substance use.
National survey of 14- to 24-year-olds found most believe cannabis is harmful during pregnancy and want clinician counseling, though over one-third would classify prenatal use as child abuse.
In a study of over 558,000 teen surgical patients, those with cannabis use disorder had 2.4x higher risk of needing mechanical ventilation and nearly 2x the risk of ICU admission.
Thirty-two clinicians across four specialties reported post-legalization increases in adolescent cannabis use, high-potency products, hyperemesis syndrome, psychosis, and parental permissiveness.
In post-legalization Washington State, cannabis use now peaks at ages 21-22 rather than declining from 18, with emerging signs of "maturing out" by 23-25 in recent birth cohorts.
ABCD Study neuroimaging of 1,085 children found prenatal marijuana exposure associated with reduced white matter integrity in tracts critical for motivation and goal-directed behavior at age 10.
Among 26,276 youth aged 12-25, the rate and severity of cannabis use disorder among users was consistent across all age groups, suggesting stable vulnerability regardless of age.
Critical review of neuroscience finds no empirical basis for the "brain matures at 25" threshold, concluding an 18-21 legal age for cannabis is scientifically supportable.
Longitudinal study of 584 Canadian emerging adults found bisexual identity strongly associated with both child maltreatment and at-risk cannabis use.
NHANES analysis found lifetime cannabis use associated with 5.45x higher odds of coronary heart disease in adults 20-59 — a striking finding that demands cautious interpretation given the cross-sectional, self-reported design.
Baseline data from 79 Australian youth found those with substance use disorders had worse depression, anxiety, and more frequent cannabis use than substance-using peers without a disorder.
Multicenter retrospective study found CBD as add-on therapy reduced median monthly seizures from 30 to 8 across multiple drug-resistant epilepsy types in children.
National ABCD Study of 2,262 adolescents found hair cannabinoid levels predicted sex-specific changes in sleep, exercise, and mental health outcomes a year later.
Survey of 260 Mumbai college students found 11.2% used cannabis, peer pressure was the top driver, and most opposed legalization while lacking knowledge of cannabis laws.
Analysis of YRBS data found cannabis legalization design matters for youth mental health: permissive and pharmaceutical bundles improved outcomes while fiscal focus worsened them.
One of the youngest reported EVALI air leak cases: a 15-year-old developed pneumomediastinum and pneumorrhachis after vaping and cannabis use.
ABCD Study found SGM youth had higher future marijuana use and past suicide attempts, but family conflict, discrimination, and trauma did not explain the disparity.
ABCD Study found childhood depression, hopelessness, and suicide attempts before age 10 predicted marijuana initiation by age 15, independent of socioeconomic factors.
ABCD Study found earlier puberty in high-income Black youth partly explains why family income is less protective against marijuana use for Black versus White adolescents.
Twin study of 232 adolescents found cannabis use linked to psychotic-like experiences, driven by environmental rather than genetic factors, with no mediation by brain connectivity.
Nationally representative survey of US high school students found higher adverse childhood experience scores significantly predicted more frequent cannabis use.
Review of prenatal cannabis exposure research found consistent links to higher ADHD risk in children, while effects on cognition, autism, and learning remained inconclusive.
Longitudinal study of rural reservation-based youth found 12th-grade cannabis use predicted 21-24% increased loneliness risk six months after high school.
Application of Bradford Hill causation criteria to longitudinal studies found substantial evidence that adolescent cannabis use may precipitate bipolar disorder in vulnerable individuals.
Decision tree analysis of 8,915 Canadian teen cannabis users found using 2-4+ times per month was the strongest predictor of problematic use, with early onset and solitary use adding risk.
NYC secret shopper study found 100% of licensed cannabis retailers verified age versus only 10% of unlicensed shops, which also featured youth-appealing products and marketing.
Study of 106,000 European teens found those who perceived COVID as negatively impacting their lives had significantly higher cannabis and other substance use.
Study of 1,847 young adults found some cannabis retail laws (billboard bans, driving warnings) achieved intended effects while many others showed no measurable impact.
Survey of 1,833 Ugandan secondary school students found 2.6% marijuana use, with male sex (2.2x odds) and mental illness history (2.9x odds) as the strongest predictors.
Rat study found smoked cannabis during pregnancy produced different and generally milder offspring behavioral changes than injected THC or CBD, with some effects resolving by adulthood.
PET imaging of 49 participants found reduced brain synaptic density in early psychosis and high-risk states, with cannabis users showing additional reductions linked to worse negative symptoms.
CDC data showed adolescent drug overdose death rates were significantly higher in cannabis-legalizing states, with recreational-legalization states showing the largest increases across sexes and racial groups.
Multi-modal profiling of HIV-positive youth found marijuana alone linked to anti-inflammatory immune changes, while tobacco use (alone or with marijuana) drove pro-inflammatory responses.
Daily diary study found male college students were 7 times more likely to use cannabis the day after experiencing cyber dating abuse, while women showed no such pattern.
Irish longitudinal study of 4,554 youth found earlier alcohol initiation and risky teen drinking independently predicted cannabis and drug use at 20, with dose-response patterns persisting after extensive adjustment.
Survey of 3,490 Norwegian adolescents found 65% of cannabis users reported harms (averaging 4.7), with shame (44%) and adverse effects (42%) most common, predicted by early initiation and alcohol co-use rather than frequency.
Study of 115 college cannabis users found imposter syndrome was linked to more cannabis problems through a pathway of social anxiety leading to coping-motivated use.
National survey of 58,034 Americans found the sharpest increase in cannabis use occurred between adolescence and young adulthood specifically among those with low risk perception, identifying a critical prevention window.
Retrospective study of 15 children with drug-resistant epilepsy found CBD reduced seizures in 11 (2 seizure-free), with improved social participation and a good safety profile, including off-label use.
Five-year monitoring of 38 children on pharmaceutical CBD found zero detectable THC in blood at any timepoint, with CBD levels rising predictably with dose.
Two toddlers who accidentally ate cannabis edibles had THC blood levels of 45-55 mcg/L, with elimination half-lives of 22-53 hours, far slower than adult THC clearance.
Prospective study of 4,380 children found maternal cannabis use before (not during) pregnancy predicted higher autism symptoms across childhood, while continued tobacco use during pregnancy predicted autism symptoms at age 6.
Adolescent THC rerouted dopamine axon growth from the medial to the orbitofrontal prefrontal cortex in male mice, altering impulse control, while females were protected by different molecular responses.
In a 30-person crossover RCT, THC-related simulator crashes peaked 4 hours after inhalation.
Daily CBD given to young mice from weaning reduced Sertoli cells during spermatogenesis and lowered sperm viability and morphology after 34 days.
Review of case reports and 9,142 FDA adverse event reports identified potential cannabis-drug interactions in children, particularly involving enzyme inhibition of methadone, everolimus, and antidepressants.
32-year analysis found cannabis use declined among most US adolescents but not among those with suicidal thoughts or attempts, with female suicide attempters showing a persistent plateau.
Living systematic review of 276 studies found most evidence for pediatric cannabinoids is for epilepsy, with CBD showing 30-50% seizure reduction in RCTs.
ML analysis found different predictors of sustained cannabis vaping by legalization status: cigarette use and bullying in legal states vs heroin use and nicotine vaping in non-legal states.
National survey of 70,000 US adolescents found cannabinoid vaping increased across all types from 2021-2023, with 2.55 million teens vaping THC and synthetic cannabinoid use doubling among youngest students.
Meta-analysis of 31 studies found male, older, White adolescents who use alcohol or tobacco had the highest odds of vaping cannabis, with Black adolescents having lower odds.
Parents of children with sickle cell disease expressed concerns about medical marijuana similar to their concerns about opioids, with societal stigma as a major barrier to treatment acceptance.
Interviews with 40 US teens found most viewed cannabis as more acceptable than alcohol, citing alcohol's worse health effects, higher addiction risk, and more aggressive intoxication.
Systematic review found 15 Canadian youth DUIC prevention initiatives since legalization, but limited evidence that any changed actual driving behavior.
Pilot RCT of a smartphone app for youth cannabis-impaired driving showed positive reception and preliminary efficacy, but faced significant recruitment and retention challenges.
Experiment with 2,523 young adults found copycat cannabis packaging reduced correct identification by 65%, highlighting accidental ingestion risks.
Experiment with 4,500 young adults found plain cannabis packaging boosted warning recall by 47% and reduced appeal, while health claims on packages increased appeal.
Study of 70 adolescent smokers found daily cannabis users wanted more cigarettes but were more sensitive to price increases than non-cannabis users.
A cannabis harm-reduction app co-designed with young adults scored 4.43/5.0 on usability and is now being evaluated for efficacy.
Parents are increasingly giving children unregulated CBD products despite FDA approval only for specific epilepsy — with concerns about product quality, drug interactions, and absent pediatric evidence.
Synthetic cannabinoids found in vapes at 78% of 27 English secondary schools tested, with prevalence tied to socioeconomic deprivation.
Survey of 4,031 young adults found cannabis-using parents nearly tripled their odds of using cannabis.
Study of 1,359 young adult cannabis users identified four spending profiles. Higher-spending groups reported more problematic use.
European longitudinal study finds genetic risk for cannabis use disorder is associated with impulsivity, novelty seeking, and white matter brain changes as early as age 14.
30 years of YRBS data: Black youth have highest cannabis-only use (12.6%), AI/AN youth have highest co-use (20.1%). Disparities have persisted since 1991.
Global data: cannabis use disorder affects 10.7 million young people (ages 10-24), second only to alcohol (13.3 million). Europe and the Americas have the highest burden.
Policy analysis: each $1 increase in e-cigarette taxes reduced teen marijuana use by 1.0-1.5 percentage points. No effect on harder drugs. Effects fade over time.
223 teens seeking to quit vaping: 92% also use cannabis, 69% in the past month. Heavier cannabis use linked to more frequent nicotine vaping.
In a prospective study of 9,116 pregnant individuals, biologic testing detected nearly three times more cannabis use than self-reports, with the gap widening as pregnancy progressed. Younger age, being unmarried, and high stress were associated with underreporting.
Prenatal THC exposure reprogrammed dopamine receptor expression in the prefrontal cortex of adolescent rats through epigenetic changes, with male offspring showing the strongest effects on D2 receptors, neuron excitability, and neural guidance systems.
A study of over 6,000 children found that maternal cannabis use around pregnancy was linked to behavioral problems specifically in children with autism symptoms, suggesting that neurodevelopmental vulnerability may modify the effects of prenatal cannabis exposure.
A natural experiment comparing Canadian and US young adults found legalization was associated with less decline in cannabis use over time (attenuated aging out) rather than increased use, with effects emerging 6-12 months post-legalization.
A study of 512 California young adults found each increase in cannabis flower potency was associated with 3.3 more use days per month and higher addiction scores, contradicting the assumption that people use less of stronger products.
Among 338 young adults, those who primarily vaped cannabis concentrates showed increasing use and problems over time, while edible users had fewer issues due to less frequent use, suggesting different consumption methods carry different addiction risks.
A 30-day tracking study found that the consequences of different cannabis consumption methods varied based on how often individuals used each method, with infrequent edible users experiencing more negative effects than frequent users.
The first trial of medicinal cannabis in teenagers with Tourette syndrome found significant improvements in tics, behavior, and quality of life, with tiredness as the most common side effect.
German survey data from 2008-2023 show stable cannabis use among adolescents but significant increases among young adults aged 18-25, providing a baseline before the country's 2024 partial legalization.
The first placebo-controlled trial of medicinal cannabis for Tourette syndrome in teenagers found the protocol was feasible, with some signal of benefit and dizziness as the most common side effect.
A survey of nearly 83,000 Minnesota students found regular cannabis use was dramatically higher among youth with multiple marginalized identities, reaching 24.8% in one 8th-grade subgroup versus 1.8% overall.
A UK early access program found pharmaceutical CBD reduced motor seizures by a median 60% at 12 months in 26 children with Lennox-Gastaut or Dravet syndrome, with 67% achieving at least 50% improvement.
Massachusetts school data from 2005-2019 showed cannabis-related discipline increased 34% after decriminalization but then declined 45% after medical legalization and 20% more after recreational legalization.
A 14-day study of 590 young adults identified six patterns of substance use days, with cannabis involved in four of the six patterns and multimodal cannabis use linked to the highest stress and boredom.
A child died after eating hashish, with forensic analysis revealing chronic exposure to multiple drugs including THC, cocaine, heroin, and fentanyl.
Among 18-20 year old cannabis users in LA, use frequency stayed stable after legalization, though edible consumption increased.
Protocol for a 200-teen RCT testing whether 8 weeks of cannabis abstinence reduces depression and suicidal ideation — using 8 daily phone surveys to capture the moment-by-moment relationship.
First-episode psychosis patients who showed cognitive deterioration had higher cannabis exposure and environmental risk scores than those who maintained cognitive function.
Brazilian LGBTQ+ youth, especially those assigned female at birth, had nearly double the odds of cannabis use and started using substances earlier than heterosexual cisgender peers.
Males with a specific MAOA gene variant who experienced childhood sexual abuse were more likely to use cannabis for coping, but this combination was associated with lower aggression.
Cannabis use among Washington State young adults continued rising through COVID while alcohol, cigarette, and e-cigarette use declined.
Depression was associated with 30% higher odds of frequent cannabis use among Black college students.
Black college students who started marijuana before 14 were 3x more likely to report suicidal ideation.
Adolescents with incarcerated family members had significantly higher odds of early and current cannabis, alcohol, and nicotine use.
Lifelong dietary fatty acid composition influenced adult rat behavior and modified adolescent THC effects on anxiety and impulsivity.
Pediatric palliative care cannabis clinic saw reduced hospitalizations and polypharmacy across 46 patients.
Ten-year study: all young children testing positive for cannabis had child protection activation, but caregivers rarely disclosed.
Analysis of 232 pediatric delta-8 THC ingestions found a dose of 1.7 mg/kg identified 98% of cases progressing to severe toxicity, establishing the first clinical reference threshold.
Culturally tailored mobile app for Black adults with cannabis use disorder showed strong feasibility and acceptability plus preliminary efficacy signals in a 50-person proof-of-concept RCT.
Parents of youth who used cannabis described it triggering or worsening severe mental health crises, while frequently encountering healthcare providers who minimized cannabis-related risks.
A teen's nausea and vomiting were blamed on cannabis use and eating disorder — but her seizures the next day revealed acute intermittent porphyria, a rare treatable condition nearly missed due to diagnostic anchoring.
Childhood adversity increased cannabis use disorder risk across all racial groups, but the effect was strongest among Asian/Pacific Islander respondents and interacted with age of onset in race-specific ways.
Youth in early psychosis programs described cannabis as creating family tension around psychosis risk while some family members' own use created contradictory messages and even bonding opportunities.
In a clinical trial of 192 young people, cannabis use didn't predict whether they successfully quit nicotine vaping—though co-use days showed higher vaping.
Cannabis use among young adults increased more in states with adult-use legalization than medical-only states, with retail outlet opening appearing to be the key inflection point.
Cannabis use among New Jersey young adults increased 42% within three months of adult-use retail sales, driven by increases in edibles and dried herb rather than concentrates or vapes.
THC was found in 64% of positive newborn drug screens at an Arkansas hospital, with use increasing after state legalization. Exposed infants had lower birth metrics and longer hospital stays.
Mice given THC during adolescence showed lasting social deficits, sensorimotor gating problems, and disrupted cortico-striatal brain connectivity with altered dopamine receptor balance persisting into adulthood.
Tracked 2,762 college students over a year and found anxiety predicted later hazardous cannabis use, with impulsivity traits amplifying the connection.
Disrupting cannabinoid receptors in newborn mice produced a combined ADHD/Tourette-like phenotype with vocal tics, hyperactivity, and learning deficits, especially in males.
Among 50 children with drug-resistant epilepsy treated with CBD for at least six months, 56% had meaningful seizure reduction and 16% became seizure-free.
Survey of 82,933 Minnesota students found bias-based bullying was associated with 50-68% higher regular cannabis use among youth with minoritized identities.
Survey of 484 postpartum mothers found only one-third received provider counseling about marijuana, despite 60% having ever used it.
About a third of teen dual users quit both vaping and cannabis at 7 months—and quitting vaping appeared to help with quitting cannabis too.
Rigorous trial of 192 youth found N-acetylcysteine was no better than placebo for cannabis use disorder when not paired with contingency management.
National survey of 10,361 adolescents found bisexual youth had 85% higher odds of marijuana use than heterosexual peers, with disparities varying by age and sex.
Large database study of ~9 million pediatric patients found cannabis use disorder linked to significantly higher rates of pelvic pain, bladder symptoms, and UTIs.
Analysis of 52,679 US adolescents found COVID-19 widened substance use disparities, with multiply-victimized youth reaching 3.5x higher marijuana use odds during the pandemic.
Prospective study of 16 children with severe autism found CBD-rich extract reduced internalizing behaviors after three months, with caregivers also reporting improved mental health.
A new brief therapy combining trauma writing with cannabis coping skills showed early promise in three young women after sexual assault—but needs rigorous testing.
Two-year study of 961 emerging adults found negative cannabis consequences predicted later depression more than depression predicted cannabis use, especially in women.
Systematic review of 16 prospective studies found early cannabis use onset specifically predicted cannabis use disorder, not other substance problems.
Analysis of nearly 25,000 cannabis-related ER visits found 21.7% involved syncope (fainting), with an 8.6-fold higher prevalence compared to non-users.
Survey of 84 youth in mood disorder treatment and 66 parents found most believe cannabis and CBD effectively treat mental health conditions.
Analysis of 2,282 cannabis edibles found most contained 100+ mg THC, with widespread use of child-appealing characters, colors, and flavors.
Experiment with 3,647 adolescents found warning labels on delta-8 THC products increased perceived risk and intoxication but did not reduce use susceptibility.
French poison centers recorded 304 cases of synthetic cannabinoid 5F-AKB48, mostly in teenage males vaping the drug, with 4% experiencing seizures or coma.
Survey of 367 college students found monthly simultaneous cannabis and alcohol use predicted depression in both sexes, with possible male-specific links to anxiety and stress.
Five-year study of 106 cannabis poisoning cases found children more often had impaired consciousness, while adults had faster heart rates and lower oxygen. Delayed treatment worsened outcomes in children.
Large study of 59,529 minority young adults found racial trauma undermined the mental health benefits of psychological well-being, with distinct patterns for multi-ethnic versus mono-ethnic individuals.
Focus groups with 28 Washington teens found cannabis edible packaging appealing despite regulations, with cannabis-knowledgeable teens showing more skepticism.
Teen cannabis use has held steady despite legalization, but ER visits, child ingestions, and product potency have all increased—changing the risk landscape.
National ER data showed suspected CHS visits among youth (15-24) topped 55,000 from 2006-2020, with an average annual increase of 28.1%.
Study of 536 teen tobacco/cannabis users found alcohol use and secondhand smoke exposure were the strongest predictors of same-day poly-product use patterns.
Study of 2,207 young adults found different types of adverse childhood experiences predicted different substance use patterns depending on racial/ethnic background.
Study of 3,823 high schoolers found same-day nicotine-cannabis use was associated with 4.28x higher odds of cannabis dependence symptoms versus using both but on different days.
Longitudinal study using both self-report and hair THC analysis found cannabis use at 20 predicted increased psychotic-like experiences, worse mental health, and poorer functioning at 24.
Denver Health data showed youth psychosis hospitalizations rose significantly after cannabis legalization, with CUD-involved cases quadrupling from 2.0 to 8.5 per 100,000 monthly.
ABCD study found light physical activity (measured by Fitbit) reduced odds of substance use initiation by 26% in adolescents, while moderate and vigorous activity had no significant effect.
Six months of daily THC during adolescence in monkeys produced persistent brain connectivity changes in reward regions and lasting motivational deficits into adulthood.
A Swedish cohort study of 3,328 adolescents found those with higher-SES parents were more likely to use cannabis, with low-SES teens showing 39% lower risk of past-year use after adjustment.
Most young vapers want help quitting, but there's no consensus on how—and 40% also vape cannabis, which they see as less harmful than nicotine.
A longitudinal sibling study found early-onset cannabis use was the strongest predictor of arrest, probation, and incarceration by age 18, outperforming childhood ADHD, oppositional behavior, and anxiety/depression.
Analysis of 7,635 young adult cannabis users across 23 states found 57% used two or more consumption methods, with recreational legalization and e-cigarette co-use among the strongest predictors.
In 4,808 adolescents, genetic predisposition to sensation seeking predicted early substance and alcohol use by age 15, while no impulsivity-related genetic scores predicted cannabis initiation specifically.
A placebo-controlled trial of 36 youth with alcohol use disorder found single-dose 600mg CBD had no effect on brain chemistry, alcohol cue-reactivity, cravings, or drinking behavior.
A survey of 8,521 German teens found those who both smoke and vape perceive cannabis as least harmful and are most likely to intend to use it, while never-tobacco-users perceive the most risk.
JAMA study of 245 teens in a pain clinic found 25% used cannabis, with 77% using it to self-treat pain, sleep, or anxiety. Users had higher pain interference and depression scores.
A review finds prenatal cannabis exposure affects multiple organ systems beyond neurodevelopment, including cardiovascular, metabolic, and growth outcomes.
Treatment-seeking adolescents used multiple cannabis products including delta-8 and delta-10 THC.
Cannabis purchase task measures predicted young adult use frequency three months later.
A survey of 24 pediatric cancer patients in a medical cannabis program found most reported symptom relief for nausea, appetite, and pain with minimal side effects.
A 9-year LA study found most young cannabis users were "Uncontrolled," but harm-reduction rules like avoiding use at work and while driving increased after legalization.
Youth cannabis use slightly decreased after Canadian legalization (15% to 12.3%), but risk factor profiles shifted toward anxiety and mental health indicators.
COVID-related stress predicted cannabis vaping in high schoolers two years later, mediated through increased susceptibility to vaping.
In 6,049 participants from the ALSPAC cohort, childhood externalizing disorders at age 10 predicted multiple problematic cannabis use trajectories from ages 15-24.
An Australian national survey found 6.2% of cannabis users met criteria for high-risk use, with daily consumption, starting before age 15, and psychological distress as the strongest predictors.
A two-year study of 3,278 Southern California teens found that how they perceived their neighborhood was a stronger predictor of cannabis and nicotine vaping than census-based measures of disadvantage.
A three-year brain imaging study found heavy cannabis users developed significant thinning in a brain region crucial for decision-making, with greater thinning linked to more severe use patterns.
A longitudinal study of 4,769 US teens found that those spending 30 minutes to 3 hours daily on social media had the highest odds of later marijuana and alcohol use.
A massive meta-analysis of 359 animal experiments confirmed that adolescent cannabinoid exposure consistently produces schizophrenia-like behavioral changes including memory impairment, social deficits, and disrupted sensory gating.
Machine learning identified a brain connectivity pattern that predicted problem cannabis use across three independent samples, including college students, European teens, and treatment-seeking adults.
Mice given THC during adolescence had reduced sperm counts and testicular damage as young adults, while the same exposure in adulthood caused milder reproductive effects.
The 2023 National Youth Tobacco Survey found home smoking exposure was the strongest predictor of teen tobacco and cannabis use, while mental stress was key for LGBTQ+ middle schoolers.
An EMA study found that college students' morning willingness and social motives predicted same-day simultaneous alcohol and cannabis use, creating a window for potential digital interventions.
An eye-tracking study found specific, concrete cannabis warning labels captured more attention and improved risk recognition among young adults compared to generic labels.
A study of 157 young people in opioid addiction treatment found cannabis use disorder predicted shorter retention, while depression and PTSD were linked to staying in treatment longer.
A trial of 150 participants found computer-based motivational interviews generated similar "change talk" about marijuana as face-to-face sessions, but only face-to-face showed a trend toward reducing actual use.
A survey of 166 young adults found that Delta-9 THC users had 20 times the odds of also using Delta-8, with complex and sometimes contradictory risk perception patterns.
Snapchat's AI chatbot freely discussed Delta-8 THC despite blocking other drug terms, providing favorable but uncited information to its predominantly young user base.
Among 1,968 young adult cannabis users, those who also used derived products like Delta-8 reported more negative consequences than cannabis-only users, with coping and enhancement motives driving co-use.
A survey of 4,031 young adults found 70% incorrectly believed derived cannabis products like Delta-8 were safety-tested and 59% thought they were FDA-approved.
Analysis of four US cannabis companies found nearly $500K spent on 399 unique ads, primarily through online displays on news websites using GIF-based visuals.
Young smokers with cannabis dependence perceived fewer downsides to smoking, and younger people preferred app-based cessation therapy over face-to-face.
A Thai multicenter study found CBD-enriched oil reduced seizures in children who had failed an average of 7 medications, with benefits sustained over 12+ months and mostly mild side effects.
A JAMA Network Open trial found a two-session personality-targeted intervention reduced cannabis use escalation by 25% over 4 years in at-risk teens, with similar effects for alcohol and tobacco.
A 14-day daily survey study found bong use predicted the most health effects among young cannabis users, with notable sex differences in how joints, edibles, and pipes affected males versus females.
A 13-year analysis of Canadian hospital data found cannabis-related hospitalizations rose 120% and ER visits rose 113%, driven largely by psychosis cases and youth intoxications.
Review explains why children are more vulnerable to cannabis intoxication than adults, with immature metabolism and unique brain receptor patterns amplifying THC effects.
Synthetic control analysis of 5 states found recreational cannabis markets increased use prevalence by 11% in teens, 17% in young adults, and 33% in adults 26+, with an 82% increase in new adult users.
Among 188 young heart attack patients (all smokers), the 41% who used cannabis had significantly worse cardiovascular outcomes over 3 years.
Study of 15,000+ Washington young adults found cannabis use rose through age 22 then plateaued, with social acceptability and low perceived harm as the strongest drivers.
Quebec birth cohort found teens who started cannabis early and used frequently had 51% more mental health visits and 86% more physical health visits by age 23 compared to nonusers.
Study of 199 youth found blood endocannabinoid levels tracked with anxiety severity, and 2-AG increases during SSRI treatment predicted better response in adolescents with GAD.
RCT of 1,078 young adults found text-message motivational treatment advanced participants through stages of change, resulting in 50% lower THC levels and 4 fewer use days at 6 months.
RCT of 1,078 young adults found text-message CUD treatment worked indirectly through increased motivation and harm reduction strategies, reducing cannabis use at 6 months.
Youth ages 15-20 built a systems model identifying 14 feedback loops showing how romantic relationship stress and cannabis use reinforce each other.
Japanese national survey found cannabis patients were younger with less severe disorders than methamphetamine patients, but less connected to recovery support services.
National survey finds only a third of US dentists screen teens for cannabis use annually, and most who screen never provide counseling, despite expressing willingness.
NYC longitudinal study found edible cannabis surpassed smoking as the most common method among young adults, with new users far outnumbering quitters.
Survey finds U.S. parents split on CBD product safety for children, with many unaware of rising pediatric poison control calls.
Missouri college students showed more positive cannabis attitudes and higher use intentions after the state legalized recreational cannabis.
Survey of 1,052 CHS sufferers finds high ER and hospital use, with heavy daily cannabis use and adolescent onset linked to more frequent episodes.
Survey of 2,204 young adults finds cannabis vape advertising exposure, especially on social media, is linked to higher use rates and frequency.
Interviews with 20 young adults at psychosis risk reveal coping motives and social pressure as top barriers to cutting back on cannabis, informing mobile intervention design.
Updated CHS management review recommends dopamine antagonists for acute episodes and treating underlying mental health conditions alongside THC cessation.
Clinicians across four specialties identify risk minimization by both teens and parents as the top barrier to treating adolescent cannabis use.
Massachusetts ER data shows CHS cases surged 14-fold from 2012 to 2021, with young adults, Hispanic, and Black populations most affected.
Warning labels on cannabis social media posts reduce sharing intentions in 1,776 people and dampen self-relevance processing in the brain, revealing the mechanism behind their effectiveness.
Study reveals two distinct pathways from ADHD to cannabis problems: inattention directly causes functional impairment, while hyperactivity drives heavier consumption leading to dependence.
Birth cohort study finds prenatal cocaine exposure leads to more marijuana use by age 21 through a chain of executive function deficits at 12 and substance use at 15.
Study of 358,391 young people across 45 countries finds cannabis use has no significant link to reduced physical activity, while tobacco use consistently does.
Activating CB1 receptors in developing zebrafish causes myelin to wrap around cell bodies instead of nerve fibers, revealing a new way cannabinoids could disrupt brain development.
National data on 40,054 teens with CUD shows only 37% complete treatment, with Black adolescents and those experiencing homelessness facing the lowest completion odds.
JAMA study of 106,032 Canadian students finds legalizing cannabis edibles increased teen use by 26%, edible consumption by 43%, and cannabis smoking by 34%.
Review finds South African medical students hold diverse views on cannabis decriminalization, with gaps in knowledge about health impacts and professional implications.
Review maps endocannabinoid system dysregulation in childhood epilepsy and outlines emerging treatment strategies beyond CBD, including allosteric modulators and enzyme inhibitors.
Study of 128 mother-child pairs finds prenatal THC exposure linked to less body fat at birth followed by rapid postnatal growth, with shorter breastfeeding amplifying the pattern.
Review finds cannabis advertising mirrors tobacco marketing tactics including price promotions and social media, with widespread exposure among youth and adults linked to increased use.
Two-hit rat study finds prenatal immune activation plus adolescent THC causes hidden brain changes visible on imaging and gene expression, even before behavioral symptoms appear.
Mouse embryo study discovers that both too much and too little endocannabinoid signaling causes catastrophic membrane ruptures in 40% of migrating brain cells during development.
National survey finds medical cannabis laws increase and perceived penalties decrease teen cannabis use, with legalization weakening the protective effect of social bonds.
Among 540 older adults across the dementia spectrum, moderate cannabis use was not associated with worse cognitive test performance—though problem use may differ.
The most comprehensive review to date (89 studies) finds prenatal cannabis exposure harmful for fetal growth and development, concluding cannabis should be avoided during pregnancy.
A narrative review of cannabis effects across the lifespan found that prenatal and adolescent exposure carries the highest neurological risk, while cannabis use among older adults is rising fastest with the least risk awareness.
A population-based Canadian study found cannabis-related hospitalizations dropped 34% among youth below the legal purchase age after legalization, while continuing to rise among adults above it.
A nationally representative study found cannabis use among young adults in the country of Georgia barely changed four years after legalization, though the drug became easier to obtain and first use shifted to older ages.
An ABCD Study analysis of nearly 10,000 children found that prenatal exposure to both cannabis and tobacco was linked to more externalizing behavior problems at ages 9-11 than exposure to either substance alone.
An ABCD Study analysis of 7,691 adolescents found that more social media time at age 12 predicted cannabis experimentation by age 14, with beliefs about cannabis effects mediating about a third of the relationship.
An ABCD Study of nearly 10,000 adolescents found that cyberbullying victims were 4.65 times more likely to try cannabis within the next year, alongside increased risks for depression and suicidal behavior.
An ABCD Study of 8,006 early teens found that social media, texting, and video chatting were linked to cannabis and other substance experimentation one year later, while TV, video games, and passive screen use were not.
Interviews with 20 young adults found stronger motivation to quit nicotine vaping than cannabis vaping, with addiction, mental health coping, and identity as key barriers, and health concerns as the main facilitator.
A 30-day daily diary study of 111 young adults found that vaping nicotine and cannabis on the same occasion was linked to the highest consumption intensity for both substances.
A study of 153 teens with mood symptoms found that cannabis users reported worse anticipatory anhedonia, with more frequent use linked to greater difficulty looking forward to pleasurable experiences.
Two longitudinal studies found prenatal cannabis exposure was linked to DNA methylation changes in neurodevelopment genes, persisting from birth through age 27 across two countries.
A scoping review of 99 neuroimaging studies found that 85% detected differences in brain structure, function, or chemistry in cannabis users aged 14-25, though research quality was generally low.
A study of 167,504 teens found five substance use patterns, including a cannabis-centered class, and all groups had higher rates of depression, suicidal ideation, and violence than non-using peers.
A review found cannabis impairs attention while nicotine enhances it in adults, but both substances harm attention development when exposure occurs prenatally.
An analysis of 47 YouTube videos found Delta-8 THC portrayed as a legal, milder cannabis alternative with easy access, while few videos were age-restricted.
A mouse study found prenatal THC combined with maternal stress caused additive harm to maternal behavior and offspring brain development, with sex-specific effects on anxiety, motivation, and gene expression.
An ABCD Study analysis of 11,858 adolescents found psychosis symptoms were already rising before cannabis initiation, supporting self-medication and shared vulnerability models alongside any direct contributing risk.
A study of 731 18-year-olds found parent cannabis use predicted offspring use, but positive parenting in early childhood significantly buffered against cannabis use disorder symptoms.
A review of 13 studies found emerging evidence that the endocannabinoid system may contribute to ADHD, with preclinical links between altered cannabinoid signaling and hyperactivity.
Experiment with 409 California youth found that cannabis ads with illustrations, food references, and positive sensation imagery significantly increased interest in cannabis use.
Placebo-controlled experiment found THC impaired cognitive efficiency more in lighter users than heavier ones, supporting the role of tolerance in moderating acute effects.
Thai poison center data showed cannabis hospitalizations rose from 69% to 97% across legalization stages, with more children exposed after recreational legalization.
Mouse study found adolescent cannabinoid exposure primed lungs for worse bacterial infections in adulthood, amplified when combined with alcohol.
Daily tracking of 65 young people in cannabis treatment showed cannabis helped sleep in the first two weeks but the benefit disappeared by week three.
Randomized trial of 29 autistic children found CBD oil did not improve social responsiveness but significantly reduced anxiety and parental stress.
Review highlights that Native American communities face unique cannabis policy challenges, with higher youth use rates and multi-jurisdictional regulatory complexity.
Study of 471 college students found eating disorder symptoms linked to cannabis use disorder, with male students showing the strongest association.
Rat study found activating cannabinoid receptors during adolescence worsened ADHD-like hyperactivity and risk-taking, with stronger effects in females.
Study of 2,303 diverse young adults found race- and gender-based discrimination linked to worse cannabis use outcomes but fewer alcohol problems.
In 107 patients with severe epilepsy syndromes, 69% achieved at least 50% seizure reduction with CBD—with genetic causes and LGS/TSC showing the best outcomes.
Analysis of 17 state cannabis policy areas from 2002-2019 found more restrictive policies consistently associated with lower cannabis use in both adults and youth.
Rat study found prenatal THC exposure during early vs late pregnancy produced opposite effects on brain immune cell activity and social behavior.
Systematic review found youth cannabis use shaped by multi-level factors: individual perceived risk, peer influence, neighborhood stress, and policy context.
Daily tracking of 65 young adults found social/environmental triggers drove cannabis use more than emotional states, challenging self-medication theories.
Review finds CHS is increasingly diagnosed in teenagers, with diagnostic delays and ineffective standard treatments highlighting the need for greater pediatric awareness.
Neonatal rat study found CBD significantly enhanced phenobarbital's antiseizure effects, supporting potential combination therapy for newborn seizures.
Culturally adapted prevention program improved emotional skills and shifted cannabis habits among Polynesian adolescents, with strongest effects in non-users and low-users.
Large prospective cohort found no significant link between prenatal cannabis use and child cognitive, motor, or language development at age 2, with an unexpected positive language association in girls.
Across 25 African countries, 3.4% of school-going adolescents used marijuana, with bullying, school skipping, and sadness consistently predicting substance use regardless of substance type.
Systematic review applying Hill causality criteria found cannabis likely contributes to schizophrenia development (OR 2.88), with adolescent use carrying roughly double the risk.
Among 508,025 Ontario children, prenatal cannabis exposure was linked to fewer primary care visits but more ER visits, hospitalizations, and psychiatrist visits through age 10.
Seven patients, mostly teens, were hospitalized with agitation and psychosis after vaping products contaminated with the synthetic cannabinoid MDMB-4en-PINACA.
Study of 105 adolescent psychiatric patients found that distorted time perspective mediated the link between trauma and PTSD severity, with PTSD symptoms in turn predicting cannabis use.
Clinical review reports youth cannabis use has actually decreased over decades despite legalization trends, while providing pediatricians with updated screening and treatment guidance.
Among 173 Arab American college students, stronger ethnic identity and religiosity were linked to lower cannabis use, with particularly strong protective effects for those with Muslim upbringings.
RCT found a culturally sensitive web-app prevention program reduced cannabis use and improved substance knowledge among 1,066 diverse college students, with effects lasting at 90-day follow-up.
A rigorous review of 8 studies found THC linked to increased psychosis risk while CBD showed potential therapeutic effects—the two cannabinoids may work in opposite directions.
Primate study found that adolescent THC exposure created lasting tolerance to cannabis cognitive effects that persisted at least a year after stopping, with higher doses needed to impair attention.
Real-time monitoring of 36 young adults found cannabis use happened mostly at home, during neutral moods, when craving, and with fewer people around, challenging emotional coping assumptions.
Rats exposed to cannabinoid receptor activation during adolescence showed lasting disruptions in hippocampal brain rhythms critical for memory—even in adulthood.
Preprint companion to RTHC-00197 with additional detail: sex-balanced cohorts and extended testing confirm lasting hippocampal theta disruptions from adolescent cannabinoid exposure.
Cannabis-related ER visits among youth aged 12-21 nearly doubled from 2018 to 2023, with increases in younger teens and females, and a 19% one-year revisit rate.
Systematic review of 33 studies found prenatal cannabis exposure linked to emerging self-regulation problems in young children, becoming more apparent after age 2 through multiple neurobiological pathways.
Multicenter study of 551 children found purified CBD reduced seizures by 50%+ in half of patients with drug-resistant epilepsy, with 14% becoming seizure-free and benefits sustained over 2+ years.
Pilot study found a neuroscience-based mobile app reduced cannabis use and improved executive function, metacognition, and decision-making in 68 college students after just four sessions.
Among 4,407 young adults, loneliness predicted 20% higher cannabis use disorder risk and more frequent cannabis use, independent of depression and other risk factors.
Clinical review finds rising pediatric cannabis edible ingestions driven by inconsistent regulation and candy-like products, providing clinical management and prevention recommendations.
A review of 60 studies mapped psychosis development: early symptoms are mostly depression and anxiety, with cannabis conferring 4-fold risk (10-fold with genetic vulnerability).
Review of 62 studies found childhood trauma plus cannabis use amplified psychosis risk up to 31-fold, with earlier onset and worse outcomes than either factor alone.
Systematic review of 38 studies finds high-potency cannabis, genetic predisposition, and environmental stressors interact to drive psychotic-like experiences in otherwise healthy people, with evidence of a bidirectional relationship.
Analysis of 1,599 Black male college students found recent marijuana use associated with 77% higher odds of moderately severe to severe depression, compounded by financial stress and racial discrimination.
Mouse study finds oral CBD and THC during pregnancy both impaired fetal growth and caused sex-dependent behavioral changes in offspring, challenging the assumption that CBD is safe for pregnant use.
First reported case of status epilepticus in a toddler from confirmed cannabis edible ingestion, requiring intubation and five-day hospitalization before full neurologic recovery.
Case report of a 16-year-old with two years of unexplained recurrent vomiting finally diagnosed as cannabis hyperemesis syndrome, emphasizing the need for CHS awareness in pediatric care.
Study of 35,437 births found prenatal THC exposure alone did not predict maltreatment after policy stopped automatically substantiating it as abuse, and revealed racial bias in testing.
Review explains why cannabis-mental health findings seem contradictory: it depends on THC vs CBD content, use frequency, age, genetics, and other often-overlooked factors.
A 21-year-old with prior cannabis psychosis developed catatonia after resuming use, triggering rhabdomyolysis, kidney injury, and autonomic instability.
Among 7,332 adolescents in the ABCD study, witnessing violence was consistently linked to stronger positive expectations about cannabis, regardless of race/ethnicity, with advantaged neighborhoods providing only modest buffering.
Longitudinal study of 715 Dutch adolescents found childhood trauma predicted earlier and faster-escalating cannabis use from age 16 to 22, but stress physiology differences did not explain the connection.
Randomized trial of 238 adolescents found that four weeks of cannabis abstinence improved inhibitory control compared to continued use, with abstinent users performing similarly to non-users by the end of the study.
Study of 80,018 Colombian students found marijuana use was associated with higher aggression, but polydrug involvement and the order of drug initiation were stronger predictors, complicating simple causal narratives.
Review describes the three phases of Cannabis Hyperemesis Syndrome in youth (prodromal nausea, severe vomiting, recovery), emphasizes frequent misdiagnosis, and calls for educational interventions in schools and healthcare settings.
NLP analysis of 13,025 adolescent health records found mood instability predicted cannabis use in both ADHD (61% higher odds) and depression (38% higher odds), with the association stronger in ADHD.
Survey of 901 college students found food restriction on substance use days independently predicted worse consequences for both alcohol and marijuana users, including those using both simultaneously.
Two teens with treatment-resistant CHS vomiting (36–45 hours) improved within 1 hour of aprepitant—a potential game-changer for acute CHS management.
Study of 95,645 Northern California teens found cannabis retail bans associated with lower psychotic disorder rates, and greater retail density linked to higher rates of anxiety and depressive disorders.
Study found socially anxious male emerging adults with high impulsivity were at greatest risk for coping-motivated cannabis use and related problems, suggesting a specific vulnerability profile.
Study of 709 Lithuanian young adults found childhood sexual abuse predicted cannabis and other substance use, while verbal abuse showed unexpected negative associations, challenging ACE summation approaches.
Analysis of 2,015 adolescents found early marijuana use (before age 13) linked to higher odds of other substance use and violence, with gambling status modifying several of these relationships.
12-month UK study found adolescents were 3.26 times more likely to develop cannabis use disorder than young adults, with baseline CUD as the other significant predictor. Use frequency, gender, and other factors were not significant.
Survey of 493 Polish students found 31% used marijuana for mental health alongside high rates of other complementary therapies, with marijuana users showing worse depressive symptoms and barriers to professional care driving self-treatment.
Meta-analysis of 220,362 adolescents across 47 countries found 7% global cannabis prevalence, with boys and high-income countries showing higher rates and Latin America leading regionally.
Study of 1,017 African American youth found polygenic risk scores for cannabis disorder did not predict cannabis initiation age, and parental monitoring interacted with genetic risk in unexpected ways.
Analysis of 2,267 young adults identified five cannabis-tobacco use patterns, with the heaviest poly-product users disproportionately representing populations facing substance use disparities.
Health assessments of 710 Aboriginal and Torres Strait Islander youth found 72% were not depressed, with absence of marijuana use among key protective factors alongside exercise, sport, and absence of other adversities.
4-week microrandomized trial of 53 young adults found neither mindfulness nor distraction text messages reduced cannabis craving at the moment it was experienced, despite excellent intervention engagement.
Survey of 2,476 high schoolers found cannabis vaping more prevalent among LGB+, Hispanic, and multiethnic adolescents, with dual nicotine-cannabis vapers showing the worst mental health and behavioral profiles.
Longitudinal sibling study of 1,261 high-risk adolescents found cannabis use was not associated with suicidal thoughts or behaviors after controlling for shared genetic and environmental influences.
Study found cannabis users and non-users responded differently to anti-cannabis campaign messages, suggesting prevention and harm reduction campaigns may need distinct approaches for each audience.
Review of comorbid cannabis use and mood disorders in adolescents found bidirectional reinforcement during a critical developmental period, requiring integrated assessment and treatment approaches.
National survey data showed adolescents with depression or bipolar disorder who use cannabis had significantly higher rates of suicidal ideation and attempts compared to non-users with the same diagnoses.
Multi-species study found daily THC causes inflammatory gliosis specifically in the adolescent amygdala through astrocyte CB1 receptors. CBD co-treatment prevented the inflammation but not all neural changes.
Postmortem testing of children under 10 showed THC positivity rising significantly from 2018-2024, with the vast majority of cases in children age 2 or younger, including 31% in newborns.
Rat study found the antioxidant N-acetylcysteine prevented cognitive, synaptic, and neurochemical damage from adolescent THC exposure, pointing to oxidative stress as a key mechanism of harm.
Study of 223,068 Australian births found children exposed to maternal cannabis use disorder had 79% higher anxiety risk and 2.5x higher PTSD risk.
Australian population study found children of mothers with cannabis use disorder during pregnancy had 3.5x higher risk of disruptive behavioral disorders across all exposure windows.
Review found the endocannabinoid system is a promising treatment target for child and adolescent psychiatric disorders, but compounds targeting it without cannabis's side effects need further development.
Daily diary study found college students with ADHD used cannabis more frequently, driven specifically by stronger motivation to cope with negative emotions.
Study of 96,482 youth found cannabis use moderated the bullying-suicidality link in LGBTQ+ teens, while opioid and hallucinogen use dramatically increased suicide attempt risk.
A study tracking teens from age 13 to 25 found early-onset escalating cannabis users had 8x higher odds of cannabis use disorder and 3x higher depression risk.
A review of 142 pediatric medical cannabis patients found 73% parent satisfaction, with epilepsy patients showing the most measurable benefit (34% seizure reduction >50%).
BC poison control data showed cannabis calls for children under 10 doubled after legalization, with edibles involved in 72% of post-legalization pediatric cases.
A survey of 3,200 parents found children exposed to secondhand cannabis smoke had 2.1x higher wheezing risk and 1.8x higher nighttime cough risk.
An expert review identifies specific developmental windows when the brain's CB1 receptor system makes youth vulnerable to lasting effects from cannabis.
College students with type 1 diabetes: 41% used marijuana, with grit and illness acceptance protective while depression increased risk.
In 11,036 adolescents, cannabis use onset altered cognitive development trajectories—and hair testing showed THC and CBD had different effects on cognition.
Longitudinal study of 387 adolescents finding that social and environmental predictors of substance initiation differ for alcohol vs. cannabis, moderated by family addiction history.
Choice experiment with 1,100 youth showing cannabis taxes reduce consumption but potency-based taxes paradoxically increase low-THC product use and may drive illegal market substitution.
Among 616 Mexican American college students who'd never used cannabis, depressive symptoms predicted starting cannabis a year later—family factors didn't buffer it.
A pilot study of 10 adolescent CHS patients found universal cannabis use disorder and specific blood profiles that may help diagnose the condition.
In a rigorous trial, pharmaceutical CBD altered brain waves and improved cognitive abilities in boys with severe autism—with blood CBD levels predicting the brain changes.
National survey of nearly 70,000 U.S. teens found THC vaping linked to depression while CBD-only vaping was associated with higher anxiety symptoms — a surprising finding that challenges simple narratives.
2023 national survey reveals 15% of Americans use cannabis monthly, with distinct age patterns: young adults favor dual cannabis-CBD use, middle-aged adults prefer cannabis-only, and seniors lean toward CBD-only.
Focus groups with 29 teens revealed same-session nicotine-cannabis use is usually deliberate — primarily to enhance the cannabis high or mask taste with flavored nicotine vapes — suggesting linked prevention is needed.
After Massachusetts legalized cannabis sales, adolescent psychiatric ER patients showed a 4.6-fold increase in cannabis disorders (3% → 12%) and 3.5-fold increase in THC positivity — the biggest impact on the most vulnerable group.
Large-scale ABCD Study analysis found prenatal cannabis exposure associated with altered brain network connectivity, cognitive differences, and mental health symptoms in children.
Analysis of 113,512 youth suicides found cannabis laws were associated with increased suicide deaths specifically among Asian/Pacific Islander (up to 42% increase) and Hispanic youth, with no effects in other racial groups.
Study of 900,000+ college students found stricter state cannabis policies associated with less cannabis use and less co-use with alcohol, with the two policy domains operating independently.
National survey finds 8.1% of US young adults co-vape nicotine and cannabis, with mental health distress, other substance use, and medical cannabis legalization as key risk factors.
Qualitative study finds young adults use cannabis during sex for enhanced pleasure, reduced anxiety, and as routine — with distinct gender patterns shaping motivations across all categories.
Researchers used focus groups and interviews with young adults to develop an 8-week text-messaging intervention promoting daily protective behavioral strategies for safer alcohol and cannabis use.
ABCD Study analysis of 7,777 children found prenatal cannabis risk was specific to post-awareness exposure, while alcohol risk was linked to pre-awareness use — timing matters differently for each substance.
Review highlights that delta-8, delta-10, and other hemp-derived cannabinoids in vaping products pose uncharacterized health risks to youth, exploiting the 0.3% THC regulatory loophole.
Daily survey study identifies four types of simultaneous alcohol-cannabis use days among college students, with 'Heavy Use' days (14% of occasions) carrying the most same-day harm.
Longitudinal study finds depression at 17 predicts cannabis problems at 23 only in sexually diverse youth, driven entirely by using cannabis to cope — a targetable pathway for prevention.
Longitudinal study of 3,437 young adults traces how cannabis laws and digital advertising shape use through risk perceptions and motives, revealing a full chain from policy to consequences.
Study finds 45.6% of young adult cannabis users also use delta-8 and similar products, driven by enhancement and coping motives, with co-use linked to more consequences in a bidirectional cycle.
Interviews with 15 young people in first-episode psychosis treatment and 16 parents reveal both want non-judgmental cannabis conversations with good information, but struggle to understand each other.
Ten-year analysis of 2,256 youth entering residential care shows hazardous cannabis use increasing — especially among girls and older teens — diverging from declining trends in the general youth population.
Meta-analysis: cannabis advertising linked to 77% higher odds of use; social media ads showed strongest effect (3.38x).
College students misusing stimulants had significantly higher cannabis use, especially nonmedical misusers.
Over a decade, the teen cannabis-distress link grew stronger, especially for frequent female users, while overall teen use declined.
A text-based mobile treatment for young adults with CUD reduced cannabis use at 6 months with equal effectiveness in rural and urban areas.
Study of 9,065 college students in seven countries finds polysubstance users had more childhood adversity, impulsivity, and ruminative thinking.
Analysis of 1,160 top YouTube videos finds hip-hop/rap 13x more likely to show nicotine or cannabis, generating over 100 billion substance impressions.
Swedish nationwide study found moderate antipsychotic doses most effective for preventing psychotic relapse after cannabis-induced psychosis — higher doses added no benefit.
Analysis of 260,000+ Swedish students over 33 years shows that rising average cannabis use among teens predictably drives increases in heavy use.
ABCD Study found racial discrimination in preteens linked to cannabis use intentions through a pathway of increased perceived accessibility and decreased perceived harm.
Longitudinal study of 293 families finds prenatal tobacco-cannabis co-exposure leads to childhood behavioral problems through emotion regulation difficulties, a different pathway than tobacco alone.
Mouse study shows prenatal cannabis exposure combined with adolescent stress increased risk-taking behavior, while neither factor alone had this effect.
ABCD Study found early adolescents follow distinct trajectories of cannabis expectancy development, with family monitoring and peer substance use as key factors.
Study of 4,270 Medicaid infants found no difference in healthcare use or developmental delay at age 3 between cannabis-exposed and unexposed babies.
Survey of 327 college students finds lack of belonging drives cannabis use indirectly through depression and anxiety, suggesting mental health support may be key.
Among 36,610 autistic individuals in Israel's largest health system, only 1.2% were prescribed medical cannabis, mostly from higher socioeconomic backgrounds with more complex clinical profiles, and most prescriptions did not meet regulatory guidelines.
A meta-analysis of 36 studies found youth cannabis users aged 15-30 had 28% higher adjusted odds of depression, 58% higher odds of anxiety, 65% higher adjusted odds of suicidal ideation, and 80% higher adjusted odds of suicide attempts.
Study of 94 Spanish cannabis treatment seekers found 88% co-used cannabis with tobacco, 76% had withdrawal symptoms (worse in women), with two distinct user profiles.
Retrospective review of 200 first-episode psychosis patients at a Soweto hospital found 73.6% had substance use, with cannabis most common at 46% and substance-induced psychosis as the top diagnosis.
Retrospective study of 29 pediatric patients with intractable epilepsy found CBD therapy had 86%+ retention at 2 years, with nearly 80% achieving at least 50% seizure reduction across diverse genetic and non-genetic causes.
Ecological momentary assessment of 88 college students found joints and blunts were associated with more hits per session and greater negative consequences compared to bong use.
Analysis of 377,205 California 11th graders found frequent cannabis use increased after 2018 retail legalization, with jurisdictions newly allowing storefronts seeing sustained elevated rates while ban jurisdictions saw declines.
PATH study data from 2016-2021 shows e-cigarette and cannabis co-use rising among young adults while cigarette-cannabis co-use stays flat or declines, reflecting a shifting substance use landscape.
Analysis of 36,161 pediatric cannabis exposures found medical dispensary openings increased young children's poisonings by 52%, but recreational dispensaries subsequently decreased them by 42%, suggesting regulatory maturation protects children.
Study of 162,532 US teens found dose-dependent links between cannabis use frequency and worse academic performance, self-regulation, and emotional states, even at monthly use levels, with younger teens more vulnerable.
Survey of 9,178 youth found earlier cannabis initiation predicted greater difficulty quitting for both American Indian and non-AI students, with AI youth more likely to start before age 14.
Study of underage US young adults found 95% of cannabis users perceived easy access and 63.5% used multiple product types, with state recreational policy increasing perceived access among non-users.
Rat study found neonatal CBD treatment reduced some immediate pain responses but failed to prevent long-term anxiety from early pain exposure, while raising safety concerns including elevated stress hormones.
Synthetic cannabinoid increased BDNF expression in adolescent rat prefrontal cortex, hippocampus, and cerebellum — potentially disrupting precisely timed brain development.
Case series documented underdiagnosed cannabinoid hyperemesis syndrome in adolescents, showing it leads to unnecessary testing and increased healthcare use.
Danish study found NAS incidence stable at 0.6 per 1,000 births, with one-third of cases not involving opioids and cannabis being the most common non-opioid substance.
ABCD Study found prenatal tobacco and marijuana exposure linked to children's behavior problems, with tobacco specifically altering connectivity between attention and default mode brain networks.
Nationally representative study of 19,000+ youth found recreational cannabis legalization linked to 45% higher odds of starting cannabis vaping, but e-cigarette use was the strongest predictor at 8x higher odds.
French surveys of 4,164 cannabis users found most buy from dealers or friends, with problematic use and being male predicting purchasing or cultivation over receiving it free.
ABCD Study found adolescents' mental health improved when household members quit cannabis, mediated by reduced family conflict and better sleep.
National survey data showed 11.4% of U.S. teens ages 12-17 use cannabis, with higher use linked to more missed school and lower grades.
Longitudinal brain imaging of 136 teens found cannabis use linked to cortical thinning (especially in males), while pre-existing brain differences also predicted who would use cannabis.
Focus groups with 28 Washington teens showed they misinterpret cannabis edible warnings, ignore nutrition labels, and find snack-like products less risky.
Study of 99,132 people in 20 legal-cannabis states found only the strongest marketing restrictions reduced exposure, while those under 21 saw the most cannabis marketing.
Large Kaiser study found adolescent cannabis use associated with significantly higher rates of psychotic, bipolar, depressive, and anxiety disorders diagnosed through age 25.
German health insurance data from 4 million youth showed cannabis-related diagnoses rose 22% (2013-2022), with 78% having co-occurring psychiatric disorders, especially depression.