Browse more cannabis research, findings, methods, and limitations.
Database study of 498,000 hand surgery patients found cannabis dependence linked to nearly double the wound infection risk and 2.5x more hospital readmissions — practical evidence for surgical risk counseling.
Daily diary study of 571 young women shows cannabis negative reinforcement in real time: experiencing emotional relief from cannabis predicts using it again the next time negative feelings arise, creating a self-perpetuating cycle.
Daily diary study found people with cannabis problems use more when anxious (coping), but also continue using for enjoyment (enhancement) — challenging the idea that addiction is purely about escaping pain.
National survey of 88,000+ adults under 50 found daily cannabis use linked to 40% higher heart disease odds, with a clear dose-response: each additional 90 days of annual use increased risk by 9%.
Review of animal studies shows prenatal THC and nicotine each disrupt development through epigenetic changes, with sex-specific effects persisting into adulthood.
Lab study of three Moroccan cannabis seed varieties found anti-inflammatory and pain-reducing properties from polyphenolic compounds, with Beldiya variety most active.
Population-level analysis of 73,000 Arkansas pregnancies found 1.6% involved medical cannabis purchases, with daily THC averaging 137mg — far exceeding therapeutic doses for non-pregnant adults.
Experiment with 686 cannabis-using drivers found that detailed health messages about cannabis-impaired driving risks accidentally increased intentions to drive high by making people feel capable of managing the risk.
Study of 1,572 gastroparesis surgery patients found cannabis users had 8x more reoperations within 90 days and 59% hospitalization rate over 5 years, while attending fewer follow-ups — a concerning pattern.
UK's largest medical cannabis registry study tracked 8,945 patients for 24 months — 78% showed quality of life improvement, with patient characteristics predicting response better than specific cannabis products.
Review finds THC disrupts male fertility through multiple pathways — reducing testosterone, impairing sperm motility and shape, and disrupting hormonal signaling via cannabinoid receptors in the testes.
Clinical study of 33 subjects found genetics significantly affect CBD processing and side effects — certain gene combinations caused 5.6x more diarrhea, pointing toward personalized CBD dosing based on pharmacogenomics.
NLP analysis of 2.6 million medical notes found cannabis use surged 900% among rheumatology patients, with Black and Hispanic patients disproportionately using for pain — highlighting both a treatment gap and health disparity.
Review of 30+ years of research shows the endocannabinoid system deteriorates with aging and more severely in neurodegeneration, but some changes are protective — offering therapeutic targets for age-related brain diseases.
Commentary reveals cannabis research is undermined by wildly inconsistent definitions — 'heavy use' ranges from monthly to daily across studies — calling for urgent standardization of how researchers identify and classify cannabis users.
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.
Rigorous natural experiment of 6 million Ontarians found living within 1km of a cannabis store was associated with 12% more cannabis-related ER visits — providing actionable evidence for store density regulation.
Large-scale ABCD Study analysis found prenatal cannabis exposure associated with altered brain network connectivity, cognitive differences, and mental health symptoms in children.
Propensity-matched study found cannabis users needed more opioids after hip and knee replacement (91-93% vs. 86-89%), had more ER visits, and hip patients had double the implant loosening at 2 years.
Preclinical study discovers CBD improves cognition after traumatic brain injury through a novel mechanism — directly binding the SET protein to activate a neuroprotective pathway previously unknown in cannabinoid research.
Case report: a patient with CHS unresponsive to standard treatments had complete symptom relief after a nerve block (erector spinae plane block) in the ER — a potential new approach for this increasingly common and frustrating condition.
Mouse study reveals cannabis smoke has opposite effects on brain inflammation depending on age — increasing it in young brains but reducing it in aged brains — potentially explaining why cannabis affects older and younger users differently.
UK registry study of 63 endometriosis patients found medical cannabis improved pain, quality of life, anxiety, and sleep over 18 months — the first longitudinal evidence for this common women's health condition.
New prospective cohort enrolled 417 pregnant women in West Virginia to track how e-cigarette and cannabis use in early pregnancy affects maternal-infant outcomes.
First nationally representative estimates show 8.2% of Americans co-use tobacco and cannabis, with the dominant pattern shifting from combustible methods in adults to nicotine vaping in youth — requiring age-tailored prevention.
A 10-week trial found that daily broad-spectrum CBD use produced WADA-prohibited cannabinoids (CBG, CBDV) in urine, with exercise significantly increasing concentrations — posing real anti-doping risks for athletes.
Analysis of 10,517 MVC trauma patients over 16 years found significant increases in marijuana-positive drivers after Pennsylvania's medical marijuana legalization, with these patients having longer hospital stays.
A small pilot trial found that CBD and THC capsules reduced specific endocannabinoid mediators in people with HIV but did not change gut bacteria composition over 12 weeks.
A national study of 30,516 US adults found that Black/African American individuals with low income or mental health conditions had up to 5x higher odds of blunt use, with disparities widening with age.
A longitudinal study of 1,745 adults found that attachment anxiety amplifies the link between cannabis use and depression, with the combination of high anxiety and avoidance predicting the greatest depressive increases.
A review of 9 MRI-based studies found prenatal cannabis exposure is linked to brain differences in multiple regions, but inconsistent methods across studies prevent firm conclusions.
A study of 53 children found that CBD (Epidyolex) reduced drug-resistant epileptic spasms by ≥50% in nearly 60% of patients, with the best results in children with Down syndrome and cortical malformations.
A study of 1,492 young Spanish adults found that most would try cannabis if legalized, with existing CBD+THC product users showing the highest demand for both medicinal and recreational cannabis.
A pilot study found that THC before bedtime increased sleep onset time and slow-wave sleep but significantly reduced heart rate variability during sleep, suggesting cardiovascular effects of nighttime cannabis use.
A rigorous crossover trial found CBD had no effect on brain excitability or sedation at either low or high doses, suggesting its anti-epileptic benefits may come from drug interactions rather than direct activity.
In one inpatient psychosis sample, cannabis users had higher MoCA scores than non-users.
A Canadian harm reduction program found that offering cannabis alongside alcohol reduced drinking: each additional joint was associated with about 2.4 fewer standard drinks per day among people with severe alcohol use disorder.
A randomized trial found 300 mg CBD improved sleep more than 50 mg CBD in high-worry individuals, but the difference from placebo was not statistically significant after 2 weeks of daily use.
A national survey of 2,271 smokers found that those with cannabis use disorder faced the highest barriers to quitting tobacco, while cannabis users without CUD showed the lowest interest in quitting.
Analysis of 35,585 adults with chronic conditions found that co-use of marijuana and opioids carried the highest depression risk (nearly 2x odds), exceeding either substance used alone.
One ED case: a “THC” gummy was analytically confirmed as HHC, with dissociative-like symptoms.
A case report describes a patient who attempted suicide after 28 days of paranoia triggered by heavy use of THC gummies and THC-A products, highlighting the dangers of cannabinoid labeling confusion.
Pharmacokinetic trial of nanodispersible CBD solution found food tripled blood absorption levels compared to fasting, with significant implications for dosing consistency.
A daily diary study of 115 young adults found that co-use days involved more drinking, and it was this higher alcohol consumption — not cannabis itself — that drove worse outcomes.
A crossover trial found that high-potency cannabis reduced alcohol cravings only in people with higher working memory, suggesting cognitive capacity determines who benefits from cannabis as an alcohol substitute.
A review of recent structural biology advances reveals how cannabinoid receptors activate and signal, laying groundwork for more precise cannabinoid-based drugs with fewer side effects.
Analysis of 13 CBD oils found hazardous contaminants including hormone disruptors (phthalates) and a carcinogenic mycotoxin (zearalenone), along with antimicrobial, neurotoxic, and genotoxic compounds.
Analysis of 28,069 people who inject drugs across 13 states found that recreational cannabis legalization was linked to 9-11% less daily opioid misuse, with racial disparities in cannabis use changes.
A study of 185,372 veterans found cannabis use disorder diagnoses surging across all groups from 2000-2022, with people living with HIV having consistently higher rates and the elderly showing the greatest relative increase.
Canadian national survey data shows the cannabis-mental health association roughly doubled from 2012 to 2022, with frequent users showing up to 5.4x higher suicidality prevalence by 2022.