A tailored web-based program helped young adults reduce their cannabis use ↗
Web-based tailored intervention reduced cannabis use in 10.8% of young adults versus 5.1% in controls, with increased intention to abstain from use.
Research library — page 33
Browse more cannabis research, findings, methods, and limitations.
Parental restriction of R-rated movies predicted lower risk of teenagers starting alcohol and marijuana ↗
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.
CBD has been shown to have anxiolytic, antipsychotic, and neuroprotective properties across multiple conditions ↗
Translational review of CBD research identifies established anxiolytic, antipsychotic, and neuroprotective properties with emerging evidence across epilepsy, PTSD, depression, and other conditions.
Nearly 6% of pregnant Colorado women used cannabis, and prenatal use was linked to 50% higher risk of low birth weight ↗
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.
Brain damage from adolescent THC exposure in female rats was reversed by boosting the body's own endocannabinoids ↗
Boosting endocannabinoid levels with a FAAH inhibitor reversed depressive behavior, restored synaptic plasticity, and rescued neurogenesis damaged by adolescent THC in female rats.
CBD reversed mitochondrial damage from iron accumulation in a model of neurodegeneration ↗
CBD rescued mitochondrial damage from iron accumulation in rat brains, restoring ferritin levels, epigenetic regulation, and enzyme activity, supporting its neuroprotective potential.
Most tweets about marijuana and pregnancy were neutral, but linked sources mostly reported negative health outcomes ↗
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.
Cannabinoids affect the brain's glial cells in ways that may be relevant to schizophrenia ↗
Review links cannabinoid receptor activity in glial cells to schizophrenia pathology, suggesting these brain support cells could be a new therapeutic target via the endocannabinoid system.
Overview of psychiatric effects of cannabinoids from acute use to chronic exposure and withdrawal ↗
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.
Synthetic cannabinoids can trigger new-onset psychosis and psychotic relapses, and their effects are more complex than natural cannabis ↗
Review found synthetic cannabinoids trigger new-onset psychosis and relapses, with effects more complex and potentially more severe than natural cannabis due to full agonist pharmacology.
Rural students started college using less marijuana than urban students but caught up by junior year ↗
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.
Hospitalized marijuana users had high rates of psychiatric admissions and increasing cardiovascular events over five years ↗
Analysis of 2.3 million hospitalizations found mood disorders topped psychiatric diagnoses (20.6%) among marijuana users, with increasing cardiovascular events and AMI as a top mortality predictor (OR 4.59).
Nearly 70% of Colorado dispensaries recommended cannabis for first-trimester morning sickness ↗
Mystery caller study found 69% of 400 Colorado dispensaries recommended cannabis for first-trimester nausea, mostly based on personal opinion, with only 32% voluntarily suggesting medical consultation.
Comprehensive review of endocannabinoid system targets for treating inflammatory and neuropathic pain ↗
Major review found endocannabinoid system targets produce reliable pain relief in preclinical models with opioid-sparing potential, though clinical translation for enzyme inhibitors lags behind.
Prenatal tobacco exposure affected girls' behavior more than boys', and toddler behavior problems predicted mothers' increased cannabis use ↗
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.
Successful tobacco quitters were more likely to not use cannabis, perceive smoking as harmful, and have no environmental smoke exposure ↗
French national survey found cannabis use predicted failed smoking cessation, while successful quitters were distinguished by no e-cigarette use, no environmental smoke exposure, and perceived harmfulness of smoking.
Childhood ADHD predicted earlier marijuana use, but twin analysis suggests shared genetics rather than a causal link ↗
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.
Cannabis use did not significantly worsen anxiety disorder outcomes after accounting for baseline differences ↗
Population study of 3,723 people with anxiety disorders found cannabis use did not predict worse remission after adjusting for baseline differences, though cannabis use disorder linked to relationship and educational disruption.
Comprehensive review of approved and emerging medical uses of cannabinoids across multiple conditions ↗
Comprehensive review cataloged six approved cannabinoid medications and evidence across pain, epilepsy, cancer, neurodegeneration, PTSD, anxiety, and addiction, spanning the full endocannabinoid system.
Cannabis dampened the brain's reward response to music, but CBD offset this effect ↗
Crossover fMRI study found cannabis dampened the brain's reward response to music in the ventral striatum and other regions, but CBD restored normal connectivity and responses.
Medical marijuana patients who used more frequently and for more conditions reported lower general health ↗
Survey of 312 LA dispensary patients found more frequent marijuana use and more medical conditions correlated with lower health, though sicker patients likely use more rather than use making them sicker.
Purified CBD reduced seizures in Dravet and Lennox-Gastaut syndromes and received FDA approval ↗
Review documents FDA-approved purified CBD (Epidiolex) significantly reducing seizures in Dravet and Lennox-Gastaut syndromes, with key drug interactions identified for clobazam and valproate.
Cannabis users had specific gene variants and altered DNA methylation patterns compared to non-users ↗
Case-control study found a CB1 receptor gene variant associated with cannabis use and higher DNA methylation at dopamine receptor genes in users, plus protective effects of education and female sex.
ED patients who used cocaine with cannabis had higher 3-year mortality than other patients ↗
Study of 1,669 ED patients found cocaine and cannabis use, both individually and combined, associated with significantly higher 36-month mortality risk after demographic adjustment.
Cannabis use among parents with children at home rose from 4.9% to 6.8% between 2002 and 2015 ↗
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.
Cannabinoids show preclinical promise for inflammatory bowel disease and colorectal cancer but clinical evidence is lacking ↗
Review found cannabinoids show preclinical anti-inflammatory and anti-tumor effects relevant to IBD and colorectal cancer, but clinical evidence remains limited to questionnaires and small studies.
A single dose of CBD increased connectivity between frontal cortex and striatum in healthy volunteers ↗
Crossover fMRI study found 600mg CBD enhanced fronto-striatal brain connectivity in 16 healthy males, offering a potential neural mechanism for its antipsychotic properties.
Cannabis decriminalization in five states cut drug arrests by 75% without increasing youth use ↗
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 activity in ways resembling patterns seen in schizophrenia ↗
THC exposure dampened human neuron gene responses to stimulation, with changes in synaptic and glutamate pathways overlapping schizophrenia, autism, and intellectual disability gene patterns.
About one-third of daily marijuana smokers in an ED survey met criteria consistent with cannabinoid hyperemesis syndrome ↗
Survey of 155 daily marijuana smokers at an urban ED found 32.9% met criteria consistent with cannabinoid hyperemesis syndrome, estimating 2.75 million Americans may be affected annually.
94% of fibromyalgia patients who used cannabis reported pain relief, though most were not medically licensed ↗
Israeli survey of 383 fibromyalgia patients found 84% used cannabis with 94% reporting pain relief, though only 44% were medically licensed and most smoked rather than using other methods.
All 26 fibromyalgia patients improved on every measure after starting medical cannabis, with half stopping other medications ↗
Small study of 26 fibromyalgia patients found all improved on every measure after medical cannabis, with 50% stopping all other medications and only mild adverse effects in 30%.
CBD may help cannabis users with early psychosis by acting as an antipsychotic and counteracting THC harm ↗
Review proposed CBD as treatment for cannabis users with early psychosis, based on evidence of antipsychotic properties and ability to counteract THC's psychotogenic, anxiogenic, and cognitive effects.
Cannabis use showed limited brain structural changes in schizophrenia and bipolar patients, except for those who started before illness onset ↗
MRI study of 314 schizophrenia/bipolar patients found cannabis use associated with limited brain structural changes, except for cortical thinning in frontal regions among those who started using before illness onset.
Comprehensive review of US cannabis trends showing increases in use, potency, and cannabis-related emergencies ↗
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.
56% of children with treatment-resistant epilepsy had at least 50% seizure reduction with CBD-enriched cannabis oil ↗
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.
70% of people with spinal cord or brain injuries used cannabis before injury, and about half continued after ↗
Colorado survey found 70% of SCI/TBI patients used cannabis before injury and 48% after, with spasticity reduction (SCI) and recreation/stress relief (TBI) as primary reasons.
Third-generation synthetic cannabinoids caused more severe poisoning with seizures in 27% and symptoms lasting 24+ hours in 34% ↗
Study of 44 ED patients found third-generation synthetic cannabinoids (AB-CHMINACA, MDMB-CHMICA) caused severe poisoning in 20%, seizures in 27%, and prolonged symptoms in 34%, exceeding earlier generation toxicity.
Regular cannabis users made up 19% of ED vomiting cases and 43% had repeat visits for the same complaint ↗
Two-year chart review found 19.4% of ED vomiting patients reported cannabis use, with 43% of regular users having repeat visits and extensive workups suggesting widespread CHS underdiagnosis.
Substance use was common among adolescent psychiatric inpatients and linked to suicidal ideation and peer use ↗
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.
Cannabis-based medicines may be cost-effective for MS spasticity, but evidence is uncertain and industry-influenced ↗
Systematic review found cannabis-based medicines potentially cost-effective for MS spasticity in European analyses, but evidence limited to 10 studies (all MS), mostly industry-sponsored, with uncertain quality of life benefits.
Teens with higher genetic risk for schizophrenia showed stronger increases in cannabis use from age 16 to 20 ↗
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.
Your Blood Carries Endocannabinoids That Track Exercise, Stress, Sleep, and Inflammation ↗
Review mapping how blood endocannabinoid levels shift with exercise, sleep, stress, pain, and metabolism — showing why cannabis affects so many different systems.
Most genetic risk for cannabis use disorder overlaps with genes affecting opportunity and frequency of use ↗
Twin study found cannabis use disorder is 78% heritable, but 83% of genetic risk overlaps with genes affecting opportunity and frequency of use, with only 17% unique to the disorder.
Systematic review found synthetic cannabinoids present in 10-13% of acute psychiatric patients and strongly associated with psychosis ↗
Systematic review found synthetic cannabinoids in 10-13% of acute psychiatric patients, associated with higher psychotic symptoms than natural cannabis, and capable of triggering new-onset psychosis.
Most studies associate cannabis use with lower sperm concentrations, though evidence on sex hormones is contradictory ↗
Review found contradictory evidence on cannabis and male sex hormones, but most studies consistently associated cannabis use with lower sperm concentrations, suggesting negative fertility impact.
Chronic THC exposure in adolescent mice triggered pro-psychotic changes in serotonin receptor signaling ↗
Mouse study found chronic THC rewired serotonin receptors toward a pro-psychotic signaling pattern via the Akt/mTOR pathway. Rapamycin blocked the effect.
A patient who smoked PCP-laced cannabis developed ECG changes mimicking a dangerous heart condition ↗
Case report of a patient who developed ECG changes mimicking critical coronary blockage after smoking PCP-laced cannabis. Coronary angiography was normal.
Adolescent brain surface area changes after starting alcohol and cannabis differed from alcohol-only users ↗
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.
A review found cannabis has not been proven to cause lung cancer but evidence remains limited ↗
Review found smoking cannabis has not been proven to cause lung cancer, while noting emerging therapeutic potential for chemo-related nausea and cancer pain. Better studies needed.