Prenatal CBD Exposure Reduced Birth Weight and Altered Early Development in Rats ↗
Prenatal CBD exposure in rats reduced birth weight and altered early neurodevelopmental behaviors at higher doses, though differences resolved by weaning.
Research library — page 94
Browse more cannabis research, findings, methods, and limitations.
4 in 10 Opioid Treatment Patients Also Used Cannabis ↗
In a study of 128 opioid maintenance therapy patients, 41% used cannabis and 73% of those met dependence criteria, with medication type influencing use patterns.
Racial Discrimination Linked to Cannabis Coping Among Asian Americans During COVID ↗
Survey of 3,159 Asian Americans during COVID-19 found racial discrimination was specifically linked to cannabis use for coping, while general pandemic stress drove alcohol and tobacco use.
CBD Reduced Binge Drinking in Mice Through an Unexpected Brain Mechanism ↗
CBD dose-dependently reduced binge-like alcohol drinking in mice, with the effect maintained over repeated dosing and evidence pointing to a novel neuropeptide S receptor mechanism.
NICU Policies on Cannabis and Breastfeeding Vary Widely Across the US ↗
Survey of 187 US NICUs found wide variation in cannabis screening and breast milk feeding policies, with 60% imposing restrictions on THC-positive mothers regardless of state legalization status.
Canada's Cannabis Surveillance Is Broken: Outdated Tools Miss the Harms Legalization Was Supposed to Track ↗
Seven years after legalization, Canada's cannabis surveillance still uses outdated diagnostic frameworks, excludes key populations, and can't reliably measure whether legalization has increased or decreased harms.
Where Things Stand on Medications for Cannabis Use Disorder ↗
Review of emerging CUD pharmacotherapies found no approved medications but several promising investigational compounds targeting endocannabinoid and motivational pathways.
Opening Cannabis Stores in Ontario Did Not Increase ER Visits ↗
Ontario's lottery-based cannabis retailer licensing provided a natural experiment showing no significant increase in emergency visits for cannabis, alcohol, or opioids after stores opened.
Meta-Analysis Links Prenatal Cannabis to Smaller Babies ↗
Meta-analysis of 13 studies found prenatal cannabis exposure significantly increased odds of small-for-gestational-age and low birth weight outcomes.
Many California Cannabis Users Unsure About Driving Laws Six Years After Legalization ↗
Survey of over 4,000 California cannabis users found mixed awareness of driving regulations six years after legalization, with lower knowledge linked to worse driving outcomes.
Genetic Evidence Links Substance Use to Faster Biological Aging ↗
Genomic analysis found genetic predisposition to tobacco and alcohol use causally accelerated biological aging, with mixed but suggestive evidence for cannabis use disorder.
Less Than Half of Legal Cannabis States Fund Research ↗
Analysis found only 12 of 38 legal cannabis states have actually allocated research funding, despite states navigating complex policy decisions without federal guidance.
CBD Oil Linked to Liver Injury in a Patient Also Taking Other Medications ↗
Case report of a 45-year-old woman who developed liver injury while using cannabis oil, with improvement after discontinuation, highlighting CBD as a potential hepatotoxin.
First Randomized Trial Comparing Legal and Illegal Cannabis Markets ↗
First randomized trial of legal vs illegal cannabis found a trend toward reduced misuse with regulated access, with benefits concentrated among polysubstance users.
Male Fibromyalgia Patients Were More Likely to Use Medical Cannabis ↗
Study of 3,044 fibromyalgia patients found 48% of males used medical cannabis vs 35% of females, alongside gender differences in PTSD, diagnosis age, and obesity.
Psychedelic Use, Cannabis Co-Use, and Prostate Cancer in Older Adults ↗
Analysis of 19,460 older males found exclusive psychedelic use associated with higher prostate cancer odds, while cannabis co-users had significantly lower odds than psychedelic-only users.
Among Methadone Patients With Psychiatric Conditions, Only Cannabis Use Was Elevated ↗
Study of 588 methadone patients found psychiatric comorbidity was associated only with increased cannabis use, not opioid, cocaine, or alcohol use.
American Indian Women Saw Cannabis as Safer Than Other Substances During Pregnancy ↗
Qualitative study found American Indian women viewed perinatal cannabis as medicinal and safer than other substances, with minimal provider discussion perceived as endorsement.
Cannabis Extract Reduced Cocaine Relapse in Mice ↗
A non-psychoactive cannabis extract reduced cocaine preference extinction time and blocked priming-dose relapse in mice, with serotonin receptors mediating the effect.
Teen Cannabis Use Predicted Loneliness After High School in Rural Communities ↗
Longitudinal study of rural reservation-based youth found 12th-grade cannabis use predicted 21-24% increased loneliness risk six months after high school.
Growing Evidence That Adolescent Cannabis Use May Trigger Bipolar Disorder ↗
Application of Bradford Hill causation criteria to longitudinal studies found substantial evidence that adolescent cannabis use may precipitate bipolar disorder in vulnerable individuals.
California Legalization Was Followed by Worse Cannabis Treatment Outcomes ↗
Analysis of 192,580 CUD treatment episodes found California's recreational legalization was associated with lower treatment retention and successful discharge rates.
Fibromyalgia Patients Said Nurses Could Fill Gaps in Medical Cannabis Knowledge ↗
Qualitative study found two-thirds of fibromyalgia patients were never offered medical cannabis despite years of ineffective treatment, and nursing education helped fill this gap.
Why French Cannabis Users Grow Their Own Despite Prohibition ↗
Study of daily cannabis users in France found 11-16% grew their own, primarily to control quality, with growers more likely to use cannabis therapeutically and avoid tobacco.
Young Adults Feared Opioids After Surgery and Turned to Cannabis Instead ↗
Qualitative study found young adults often underused prescribed opioids due to addiction fears and intentionally turned to cannabis for post-surgical pain and anxiety management.
Using Cannabis 2-4 Times a Month Was the Key Threshold for Problematic Use in Teens ↗
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.
Unlicensed Cannabis Products in New York Had Less Safety Info and More Youth Appeal ↗
Study of 88 New York cannabis products found unlicensed products had less safety information, less essential data, and more youth-appealing design than licensed products.
NYC Unlicensed Cannabis Shops Rarely Checked IDs and Sold Near Schools ↗
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.
Using Cannabis and Alcohol Together Made People More Intoxicated and Predicted Riskier Use Later ↗
EMA study found cannabis-alcohol co-use produced greater intoxication than either alone, with the intensity of co-use intoxication predicting hazardous cannabis use up to 12 months later.
Cannabis Did Not Appear to Weaken Immune Markers Relevant to Cancer Immunotherapy ↗
Systematic review of 40 studies found cannabis use did not meaningfully change immune parameters in clinical settings, providing some reassurance for cancer patients using cannabis during immunotherapy.
Blood THC Levels Did Not Reliably Predict Driving Impairment in Most Studies ↗
Systematic review found 10 of 12 studies showed no linear relationship between blood THC levels and driving performance, questioning THC-based impairment testing.
6 in 10 Opioid Treatment Patients Used Cannabis, Most as a Harm Reduction Strategy ↗
Survey of 118 German opioid maintenance patients found 60% used cannabis, with most using it as a deliberate harm reduction strategy to reduce heroin and benzodiazepine use.
What Happens When Countries Regulate Cannabis: Arrests Drop, Adult Use Rises ↗
Systematic review across five jurisdictions found regulated cannabis supply consistently reduced arrests and increased adult use, with health outcomes varying by regulation model.
Half of Brain Tumor Patients Had Used Cannabis, Many Without Being Told About It ↗
Survey of 100 brain tumor patients found 51% had used cannabis, with 19% using it for tumor-related symptom relief, favoring CBD over THC.
CBD Made Runners Feel Calmer but Didn't Change Their Running Performance ↗
300 mg CBD increased feelings of calm and relaxation before a 2-mile run but had no effect on running speed, heart rate, or other performance measures in 12 runners.
Cannabis Use Linked to Depression and Anxiety in Sexual Minority Young Men ↗
Cannabis use was significantly linked to depression and anxiety among sexual and gender minority young adults, highlighting the need for targeted interventions in this population.
Bisexual Women in Canada Had the Highest Cannabis Use Disparities ↗
Nationally representative Canadian data showed bisexual women had the greatest cannabis use and mental health disparities compared to heterosexual peers.
Areas With More Teen Cannabis Use Had Higher Rates of First Psychotic Episodes ↗
Italian study found area-level teen cannabis use was associated with higher first-episode psychosis rates and 12.9 months longer delays before treatment.
Meta-Analysis Confirms Cannabis Can Cause Paranoid Symptoms ↗
Meta-analysis of 13 studies found converging experimental and observational evidence that cannabis use causes paranoid symptoms, with THC-dominant products producing the strongest effects.
Cannabis Edibles Contained Up to 5,491 mg More THC Than Labels Claimed ↗
Lab testing of 12 cannabis edibles found THC content varied by up to 5,491 mg from labels, with no CBD detected in any product, highlighting severe quality control problems.
European Teens Who Felt Hardest Hit by COVID Used More Cannabis ↗
Study of 106,000 European teens found those who perceived COVID as negatively impacting their lives had significantly higher cannabis and other substance use.
Medical Cannabis and Drug Interactions in Seniors: Real-World Data from 12,599 Patients Shows Low but Real Risk ↗
Study of 12,599 Ontario seniors found those taking both medical cannabis and warfarin had higher bleeding rates — the first population-level evidence of clinical harm from cannabis drug interactions.
Some State Cannabis Laws Worked as Intended, Many Did Not ↗
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.
Oil and Concentrate Users Had the Most Problematic Cannabis Use Patterns ↗
Latent class analysis of 4,031 young adults found moderate oil/concentrate users had the worst outcomes across problematic use, mental health, and impaired driving measures.
Low-Dose CBD Enhanced Opioid Pain Relief Without Adding Side Effects ↗
Double-blind RCT found 50 mg CBD enhanced opioid pain relief and reduced psychomotor impairment without additional side effects, suggesting opioid-sparing potential.
Brief Interventions in Medical Settings Did Not Reduce Cannabis Use ↗
Meta-analysis of 17 RCTs found brief drug interventions did not reduce cannabis use in general medical settings, though emergency department delivery showed some promise.
Transdermal CBD Gel Showed Long-Term Safety in Children With Fragile X Syndrome ↗
Interim analysis of 240 children with Fragile X syndrome found transdermal CBD gel was safe over 28 months with mild side effects and encouraging behavioral improvements.
Can Breath Tests Detect THC After Eating Cannabis Edibles? ↗
Proof-of-concept study found THC appeared in breath after eating cannabis edibles, but timing and magnitude varied widely across 29 participants.
CBD Reversed Seizure Worsening Caused by Chronic Nicotine Pouch Use in Mice ↗
Chronic nicotine pouch exposure worsened seizures and brain inflammation in mice, but inhaled CBD reversed these effects by restoring brain waste clearance and reducing inflammatory markers.
A Brain Chemical Linked to Schizophrenia Made THC's Impairing Effects Worse in Mice ↗
Kynurenine, a metabolite elevated in schizophrenia, amplified THC-induced motor impairment and behavioral effects in mice, possibly by raising THC blood levels.