Most pregnant people who kept using cannabis said their reasons shifted to symptom control ↗
Survey of 105 pregnant cannabis users found 62% continued after pregnancy recognition, with those viewing use as medical four times more likely to continue.
Research library — page 70
Browse more cannabis research, findings, methods, and limitations.
Standard diagnostic criteria both overestimate and underestimate cannabis use disorder in chronic pain patients ↗
Study found standard DSM-5 criteria flagged 30% of medical cannabis patients for cannabis use disorder, but adjusted scoring accounting for therapeutic use dropped the rate to 2%.
Repeated exposure to a synthetic cannabinoid caused lasting cognitive and brain changes in mice ↗
Mouse study found 7 days of synthetic cannabinoid JWH-018 produced psychotic-like symptoms and lasting brain changes in memory, social behavior, and neuroplasticity persisting 15+ days after stopping.
Cannabis was the primary concern for 15% of people entering drug treatment in New South Wales ↗
Analysis of 14,087 Australians entering drug treatment found cannabis was the primary concern for 15%, with high rates of poor mental health and polysubstance use across all groups.
More than a third of gynecologic cancer patients used cannabis, mostly without a prescription ↗
Survey of 46 gynecologic cancer patients found 37% used cannabis for pain, anxiety, and insomnia, mostly without prescriptions or doctor involvement.
Injected vs. smoked cannabis had different effects on inflammation in pregnant rats ↗
Pregnant rat study found injected THC/CBD increased fetal inflammation while smoked cannabis reduced it, showing route of administration fundamentally changes outcomes.
One in five pregnant substance users reported using more than one substance during pregnancy ↗
Nationally representative US data showed 4.3% cannabis use during pregnancy, but screening rates for cannabis (82%) lagged behind alcohol and tobacco (~95%).
Older veterans use medical cannabis as a substitute for opioids and benzodiazepines with little guidance ↗
Interviews with 32 older veterans found they use medical cannabis to replace opioids and benzodiazepines, but face inconsistent VA policies and minimal physician guidance.
Cannabis use during pregnancy linked to prematurity and smaller babies in French hospital data ↗
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.
Synthetic cannabinoid caused lasting brain metabolism changes and memory deficits in adult mice ↗
Mouse study found synthetic cannabinoid WIN 55,212-2 caused lasting brain metabolism reductions and memory deficits that persisted after prolonged abstinence, especially when exposure occurred in early adulthood.
CBD reversed social behavior and brain changes caused by adolescent binge drinking in rats ↗
CBD reversed social behavior deficits, abnormal stress responses, and brain plasticity changes caused by adolescent binge drinking and social stress in a rat model.
Teens with PTSD or anxiety experienced greater positive mood boost from cannabis use ↗
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.
Cannabis products labeled indica and sativa had different effects on cognitive effort in rats ↗
Rats given oral cannabis oil labeled indica were less willing to exert cognitive effort for rewards compared to sativa-labeled oil with identical THC/CBD content, suggesting other compounds matter.
Cannabis use and cannabis use disorder strongly linked to mental health conditions in pregnant and postpartum women ↗
National US data found pregnant and postpartum women with mental health disorders had 2-12 times higher odds of cannabis use disorder, with 9.8% overall cannabis use prevalence.
CBD and cannabis extracts reduced the effectiveness of platinum chemotherapy drugs in cell models ↗
Cell culture study found CBD and cannabis extracts reduced the effectiveness of platinum chemotherapy drugs by decreasing how much drug accumulated inside cancer cells.
Dispensary staff broadly view medical cannabis as beneficial and low-risk ↗
National survey of 434 dispensary staff found overwhelming positive views of medical cannabis benefits and minimal concern about risks, raising questions about balanced patient guidance.
School-based substance prevention programs showed mixed and sometimes counterproductive results ↗
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.
Colorado county-level cannabis access showed mixed effects on opioid prescribing ↗
Colorado county-level analysis found recreational cannabis access reduced opioid prescription fills and inpatient visits but not total opioid consumption or ED visits.
Anxiety disorders drive most of Australia's 300,000 medical cannabis prescriptions for psychiatric conditions ↗
Australia's ~300,000 medical cannabis approvals showed one-third were for psychiatric conditions, dominated by anxiety disorders, often for conditions with limited clinical evidence.
Presenting scientific facts about cannabis shifted public attitudes in a Mexican state known for drug trade ↗
After receiving scientific information about cannabis, 3,162 residents of Sinaloa, Mexico shifted toward more positive or neutral views, with education and age moderating the effect.
Cannabis use at work nearly doubled injury risk, but off-the-job use did not ↗
Longitudinal study of 2,745 Canadian workers found cannabis use at work nearly doubled injury risk, while off-the-job use showed no increased risk.
Alcohol and tobacco changed thousands of DNA methylation sites, but marijuana showed no significant effects ↗
Study of 3,424 adults found alcohol altered 2,569 DNA methylation sites and tobacco 528, but marijuana showed no significant changes, with alcohol-related methylation mediating hypertension risk.
CBD improved memory in adolescent rats that were exposed to THC before birth ↗
CBD given during adolescence rescued memory deficits and restored brain plasticity markers in rats prenatally exposed to THC, suggesting a potential therapeutic window.
Prenatal care providers avoid cannabis conversations to maintain patient trust ↗
Qualitative study of 10 maternal health providers found they often avoid cannabis conversations with pregnant patients to maintain therapeutic relationships, despite recognizing this leaves patients without guidance.
More Americans now believe cannabis smoking is safer than tobacco, but science doesn't fully support that view ↗
JAMA study found 44% of US adults now view daily cannabis smoking as safer than tobacco, up from 37% in 2017, a perception that diverges from existing evidence on smoke risks.
Genetic evidence suggests cannabis use disorder may lower educational attainment, while education reduces disorder risk ↗
Genetic analysis found cannabis use disorder may reduce education by 1.2 months, while higher education was associated with more lifetime cannabis use but 61% lower disorder risk.
CBD reduced Alzheimer's-related brain damage and improved cognition in mice ↗
Mouse study found CBD protected against Alzheimer's-related cognitive deficits by modulating microglial activity and inflammatory gene expression.
Secondhand marijuana smoke reached concerning levels at golf courses and other outdoor locations ↗
Pilot study found secondhand marijuana smoke PM2.5 levels up to 149 ug/m3 at golf courses and public parks, with over 20% of golf course visits encountering exposure.
Genetic overlap between cannabis use and psychotic disorders suggests shared biological roots ↗
Lancet Psychiatry study found significant genetic overlap between cannabis use and schizophrenia/bipolar disorder, with evidence of causal effects running in both directions.
Cannabis use did not predict who developed psychosis among those already at clinical high risk ↗
Prospective study of 334 people at clinical high risk of psychosis found no association between baseline cannabis use and transition to psychosis over 2 years.
Cannabis for childhood cancer symptoms showed promise but rigorous dosing data is lacking ↗
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.
Personalized feedback based on genetic risk factors reduced cannabis use in college students ↗
Pilot RCT found a personalized feedback program targeting sensation seeking, impulsivity, and other risk traits significantly reduced cannabis use in college freshmen.
Young children and polysubstance use predicted severe outcomes from pediatric cannabis intoxication ↗
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.
Oklahoma cannabis dispensaries concentrated in underserved areas with fewer pharmacies and more uninsured residents ↗
Analysis of 1,046 Oklahoma census tracts found dispensaries concentrated in areas with more uninsured residents and fewer healthcare outlets.
Cannabis marketing exposure linked to more positive attitudes and greater use in Oklahoma ↗
Survey of 5,428 Oklahoma adults found 75% reported cannabis marketing exposure, which was associated with more positive attitudes and greater cannabis use.
People with suspected cannabinoid hyperemesis syndrome remain skeptical about the diagnosis ↗
Interviews with 24 chronic cannabis users with cyclic vomiting found widespread skepticism about the CHS diagnosis and frustration with cessation-only treatment recommendations.
Youth-appealing cannabis packaging drew more eye attention to fun features and less to warning labels ↗
Eye-tracking study of 72 young adults found youth-appealing cannabis edible packaging increased product appeal and reduced attention to warning labels.
Cannabis and cocaine use in pregnancy rose sharply over a decade in Dublin while opioid use fell ↗
Dublin maternity hospital data showed cannabis and cocaine use in pregnancy nearly quadrupled from 2010-2019 while opioid use declined, with high rates of complications.
Telehealth program promoting cannabis-free activities showed promise for untreated cannabis use disorder ↗
Pilot telehealth intervention promoting cannabis-free activities for untreated CUD achieved 70% completion with preliminary reductions in use, depression, and anxiety.
Cannabis legalization in Canada did not increase self-harm rates in Ontario or Alberta ↗
Interrupted time series found no increase in self-harm ED visits or hospitalizations in Ontario or Alberta following Canadian cannabis legalization.
Three distinct profiles of cannabis treatment patients predicted very different long-term outcomes ↗
Study of 2,055 CUD patients found three treatment profiles, with 80% of high-adherence patients relapse-free at 2 years versus 24% in the moderate group.
Nearly one in five Jamaican adolescents used marijuana recently, with psychosocial risks as key correlates ↗
National Jamaican survey found nearly 20% of adolescents used marijuana recently, with loneliness, suicidal ideation, and parental smoking among key correlates.
Medical cannabis improved quality of life for inflammatory bowel disease patients in a UK registry ↗
UK registry study of 76 IBD patients found medical cannabis improved disease-specific quality of life, anxiety, and sleep at 1 and 3 months.
Psychological distress nearly tripled cannabis use frequency among pregnant women in the US ↗
Analysis of 3,373 pregnant US women found serious psychological distress associated with nearly 3x more cannabis use days and 5x more binge drinking days.
Cannabis-using older drivers were pulled over more often but did not have significantly more crashes ↗
Study of 2,095 older drivers found cannabis users had 58% more traffic stops but no significant increase in crashes, possibly because they rarely drove after use.
One-third of fibromyalgia patients used medical cannabis despite limited evidence-based guidance ↗
Survey of 63 fibromyalgia patients found 35% using medical cannabis, alongside widespread use of opioids and NSAIDs that contradict clinical guidelines.
No high-quality evidence supports cannabis for anxiety, depression, or insomnia in cancer patients ↗
MASCC systematic review of 15 RCTs found no high-quality evidence for cannabis treating anxiety, depression, or insomnia in cancer, though sleep showed some promise.
One in five young pregnant women had tried CBD products, linked to prior substance use ↗
Study of 186 young pregnant women found 20% had tried CBD, with pre-pregnancy substance use as the strongest predictor.
THC was prescribed only to severely ill children in Vienna, with significant documentation gaps ↗
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.
Social class, race, and gender shaped whether marijuana promoted or harmed well-being among Brazilians ↗
Brazilian survey of 2,637 adults found marijuana's well-being effects shaped by race, gender, and class, with Indigenous peoples and youth most harmed by prohibition.