Browse more cannabis research, findings, methods, and limitations.
First study of COPD patients finds combined cannabis+tobacco smoking produces higher lung volumes and 4x more bullous emphysema than tobacco alone, suggesting distinct cannabis lung damage.
France's 3-year medical cannabis program found 3% of 3,164 patients had serious adverse reactions — neurological, GI, and psychiatric dominant — with no psychosis and only 1 case of misuse.
Updated systematic review of 25 RCTs found THC products slightly reduce chronic pain but with significant side effects; CBD-dominant products showed no benefit.
Over 30 semi-synthetic cannabinoids derived from hemp CBD are circulating in Europe with unknown safety profiles, posing challenges for regulation and detection.
Lab study found CBD activated anti-aging pathways SIRT1 and autophagy in stem cells, preserving their function and delaying cellular aging — a potentially significant finding for regenerative medicine.
Pilot study found postpartum cannabis users averaged 24 days/month of use, with THC confirmed in breastmilk, and reported mostly negative interactions with healthcare providers about their cannabis use.
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.
Survey of 322 college students found LGBTQ+ students experienced more lifetime trauma and riskier cannabis use, with trauma identified as the mechanism linking identity to cannabis harm.
Study of 40 knee replacement patients found the body's endocannabinoid system actively responds to surgical pain, with lower anandamide levels linked to higher pain — opening doors for non-opioid pain strategies.
Systematic review of 11 studies found 3-21% of people with anxiety disorders also have cannabis use disorder, with rates potentially reaching 34% among veterans with PTSD.
Study of 396 mother-child pairs found that children exposed to both tobacco and cannabis smoke had higher nicotine metabolite levels than those exposed to tobacco smoke alone — evidence of additive harm.
Mouse study reveals that CB1 receptors on astrocytes paradoxically promote MS-like disease by weakening the blood-brain barrier, while CB1 on neurons and oligodendrocytes is protective — highlighting the complexity of cannabinoid effects in neuroinflammation.
Case report of a 26-year-old man who developed life-threatening lung bleeding (diffuse alveolar hemorrhage) linked to cannabis smoking plus a viral respiratory infection — a rare but serious adverse event.
National data shows cannabis poisoning ER visits rose 70% from 2016-2019, but per user, cannabis caused far fewer emergencies, admissions, and deaths than heroin, cocaine, benzodiazepines, or alcohol.
National survey data shows cannabis-only use nearly tripled (3.9% → 10.6%) while cigarette-only use nearly halved (15% → 8.8%) from 2015-2023, with a striking socioeconomic inversion between the two substances.
Scoping review of RCTs found thin and mixed evidence for cannabis treating mental health conditions — CBD shows some anxiety promise but most psychiatric evidence remains inconclusive.
Systematic review of 57 studies and 971 patients found prescription CBD (Epidiolex) reduced seizures across 37 different rare epilepsy types beyond its three approved conditions, with some patients achieving seizure freedom.
Review of 16 studies found medical cannabis may improve pain, sleep, appetite, mental health, and reduce opioid use in cancer patients — promising but in need of more rigorous clinical trials.
Proof-of-concept study in 7 opioid use disorder patients found CBD improved heat pain tolerance in those on buprenorphine but not methadone, with excellent safety at doses up to 1200mg — suggesting medication type matters for CBD pain relief.
Survey of 5,167 university students across 6 countries found significant cross-national differences in how dangerous cannabis and alcohol impaired driving are perceived, with implications for targeted prevention.
Review of PET brain imaging studies reveals distinct endocannabinoid system alterations across five psychiatric disorders — offering a window into how the brain's cannabis system goes awry in mental illness.
Longitudinal mouse MRI study found prenatal THC caused enlarged ventricles in embryos followed by sustained brain growth deceleration into adulthood, with females more affected.
Gold-standard placebo-controlled trial of 120 people found cannabis impairs 10 of 13 memory types tested — including everyday memory like remembering plans and event sequences — with no difference between moderate and high doses.
Study found over half of young Black men who only smoked cannabis blunts had nicotine levels exceeding secondhand smoke exposure — despite reporting no tobacco use — revealing hidden addiction risk.
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.
NHANES analysis of 4,400+ adults found recreational exercise linked to less cannabis use, while sedentary behavior and work-related activity linked to more — suggesting the type of physical activity matters.
First study using teacher assessments found CBD-rich cannabis oil significantly improved hyperactivity, anxiety, and emotional regulation in 53 children with autism over 3-6 months — promising but uncontrolled.
Genomic analysis reveals education and cannabis share 84% of causal genetic variants, but in opposite directions — genes promoting education also promote trying cannabis while protecting against cannabis use disorder.
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.
87-day daily diary study of 74 veterans found cannabis predicted less next-day depression for veterans without PTSD, but this mood benefit disappeared in veterans with PTSD — complicating the self-medication narrative.
Survey of 575 cannabis users found overwhelming preference for standardized THC dose labels (like '5mg per serving') over percentages — supporting a 'standard drink' approach for cannabis.
Interviews with 15 Australian medical cannabis users found telehealth access is easy but costs remain prohibitive, with many using cannabis for both medical and recreational purposes — blurring regulatory boundaries.
Cell studies found four cannabis extracts — THC-rich, CBD-rich, and CBN-rich — all reduced Parkinson's-related protein clumps and showed antioxidant effects, suggesting broad neuroprotective potential regardless of cannabinoid profile.
Review of preclinical evidence shows CBD protects brain support cells (glia) after stroke by reducing inflammation, oxidative stress, and barrier damage — a promising multi-target neuroprotective approach.
Case report: 27-year-old cancer survivor completely replaced 120mg/day opioids with medical cannabis within 4 weeks, maintaining pain control at VAS 2-3 with unexpected resolution of a chronic infection over 9 months.
Experimental study found that among trauma-exposed cannabis users, negative thoughts about oneself — but not self-blame or negative world views — specifically drove cannabis cravings after trauma cue exposure.
Study of 1,406 cannabis users found 28% had problematic social media use — higher than population norms — with TikTok, Twitter, depression, and cannabis risk all contributing factors.
Comprehensive review maps extensive overlap between migraine pathways and the endocannabinoid system, identifying multiple therapeutic targets for patients who don't respond to current treatments.
National data shows states with legal recreational cannabis sales had 2x higher binge drinking during pregnancy, with legalization associated with a 5 percentage point increase — an unexpected and concerning connection.
National database study found cannabis use disorder didn't worsen heart surgery outcomes after matching, but CUD patients had dramatically higher rates of polysubstance use.
National survey of 25,000 Australian workers found 5% use cannabis weekly, with at-risk users missing nearly 7 extra work days annually — concentrated in construction, hospitality, and trades.
Large prospective study of 15,378 women over 65 found past cannabis smoking linked to 27-30% higher odds of cognitive complaints, with regular smokers at 61% higher risk — a dose-dependent association persisting decades after use.
Comprehensive preclinical study showed CBD reduced alcohol dependence across every dimension tested — consumption, withdrawal, anxiety, relapse, and brain damage — while leaving non-alcohol rewards unaffected.
Daily diary study of 496 young adults using hundreds of statistical models found no evidence that bad moods drive cannabis use, and negative affect actually reduced alcohol use — fundamentally challenging self-medication theory.
Registered report studying 496 young adults over 32 days found emotional impulsivity (urgency) does not amplify the mood-substance use link for either cannabis or alcohol — challenging a core addiction theory.
Computational study modeled CBD's interactions with five brain receptor types involved in seizures, finding multi-target binding that may explain its broad anti-epileptic activity.
Scoping review found CBD failed to beat placebo for cocaine addiction in clinical trials despite promising animal data — well-tolerated but not effective as standalone treatment, highlighting the preclinical-to-clinical translation gap.
Systematic review confirms CBD potently inhibits liver enzymes (CYP3A4, CYP2C9, CYP2C19) that process 80% of medications — a critical safety concern for the millions combining CBD with prescriptions.
Systematic review shows CBD has multi-target anti-cancer activity — inhibiting growth, triggering cell death, blocking spread, and modulating immunity — but almost all evidence is preclinical and clinical trials are urgently needed.
Large Canadian study of 215,000+ people found medical cannabis patients had 15% higher risk of heart failure ER visits and hospitalizations compared to matched controls — a modest but clinically meaningful signal.