Browse more cannabis research, findings, methods, and limitations.
A survey of 46 budtenders found most viewed cannabis as beneficial for mental health, especially for sleep and depression, but their perceptions often did not align with scientific evidence.
A national analysis of 3,167 dispensaries found they were twice as likely to be in neighborhoods with high Black populations and far less likely in areas with high homeownership.
A JAMA Health Forum study of 3 million cancer patients found medical cannabis dispensary openings linked to 41 fewer patients per 10,000 receiving opioid prescriptions and shorter supply durations.
CBD reduced depression-like symptoms and protected memory in socially isolated mice, but unexpectedly increased anxiety in non-stressed mice, highlighting CBD's context-dependent effects.
Advanced cancer patients vaporizing cannabis for appetite reported eating benefits and tolerated psychoactive effects well—some even enjoyed them.
Analysis of 740 cannabis driving cases in Germany found THC blood levels were too weakly correlated with impairment to define a useful legal threshold, and the new 3.5 ng/mL limit would remove one-third of current offenses.
A Thai multicenter study found CBD-enriched oil reduced seizures in children who had failed an average of 7 medications, with benefits sustained over 12+ months and mostly mild side effects.
National Medicaid data showed substance use disorder prevalence quadrupled among autistic adults from 2012 to 2016, with cannabis disorders particularly elevated in those aged 30-64.
Mouse study found sesame oil delivered far more CBD and THC to tissues than omega-3 oils, and different carriers directed cannabinoids to different organs, with DHA oil favoring the brain.
A JAMA Network Open trial found a two-session personality-targeted intervention reduced cannabis use escalation by 25% over 4 years in at-risk teens, with similar effects for alcohol and tobacco.
A review found the endocannabinoid system regulates fear and extinction learning in PTSD, with preliminary evidence that cannabinoid-based treatments like nabilone can help, though self-medication carries risks.
A study of nearly 3,800 medical cannabis patients found 25% had suicidal thoughts at treatment entry, with rates declining over 12 months, though the observational design limits causal conclusions.
A controlled trial of 42 dogs found CBD/THC extract added to standard painkillers did not improve pain, mobility, or recovery after knee surgery compared to placebo.
CBD reduced seizures and brain damage in rats with post-traumatic epilepsy by targeting the TRPV1 channel, suggesting a potential preventive treatment for epilepsy after brain injury.
A genetic study found social isolation causally increases cannabis use disorder risk by over 4-fold, with depression acting as a key mediator explaining about 22% of the effect.
A 14-day daily survey study found bong use predicted the most health effects among young cannabis users, with notable sex differences in how joints, edibles, and pipes affected males versus females.
Brain imaging in rats showed THC increased connectivity and blood flow while CBD decreased connectivity, and combining them produced moderate effects, providing biological evidence for how CBD moderates THC.
A metabolomics study identified blood markers that distinguished cannabis intoxication from mere use with 80% accuracy, potentially solving the problem of detecting actual impairment rather than just consumption.
Mystery calls to 104 Arizona dispensaries found 71% of budtenders recommended cannabis for morning sickness, with only one-third proactively suggesting medical consultation first.
A meta-analysis of 25 studies found cannabis use linked to suicidal thoughts (46-78% higher odds) and attempts (117% higher in teens) even after accounting for depression, though depression partly explains the connection.
Among 206 pregnant women with opioid use, over 80% used tobacco (unchanged across trimesters) and about 30% used cannabis in early pregnancy, declining to 17% by the third trimester.
Among 13,477 ED patients with substance diagnoses, cannabis-related conditions were linked to 21% higher overdose odds, with Black, Hispanic, and publicly insured patients at disproportionate risk.
A 13-year analysis of Canadian hospital data found cannabis-related hospitalizations rose 120% and ER visits rose 113%, driven largely by psychosis cases and youth intoxications.
Lab study found two common synthetic cannabinoids promoted nerve cell growth through CB1 receptors while simultaneously damaging mitochondria, raising concerns about neurodevelopmental effects.
In a mouse model of pancreatic cancer, CBD alone extended survival and altered gut bacteria and bile acid metabolism, while THC and the THC-CBD combination did not improve outcomes.
A review describes how new biosensor and imaging technologies are enabling researchers to track endocannabinoid signaling at individual synapses in living brains for the first time.
A 16-year study of 52,000+ psychiatric admissions found cannabis users were more likely to need intensive care during the 3-5 day cannabis withdrawal window, especially women and older adults.
Rat study found ketamine does not mimic THC or morphine effects but combining ketamine with THC produced notable sedation, relevant for clinical and recreational polydrug use.
Survey of 1,045 Pennsylvanians found rural residents were less likely to tell doctors about marijuana use, potentially harming medical care quality due to stigma.
Review explains why children are more vulnerable to cannabis intoxication than adults, with immature metabolism and unique brain receptor patterns amplifying THC effects.
Meta-analysis of 8 studies found cannabis users had 31% higher odds of asthma diagnosis than non-users, with consistent results across sensitivity analyses.
Small study of 58 pain patients found a dopamine-related gene variant significantly influenced THC blood levels, with biomarker differences between inhaled and oral cannabis routes.
Mouse study shows CB1 cannabinoid receptors are essential for maintaining the blood-testis barrier during sperm production, with deletion causing barrier leakage and slower spermatogenesis.
A drug that boosts natural endocannabinoids by blocking their degradation enzyme relieved both acute and chronic migraine pain in mice without losing effectiveness over repeated dosing.
Analysis of millions of VHA patients from 2005-2022 found cannabis legalization was associated with small increases in opioid use disorder, with the largest effects in older adults with chronic pain.
Study of nearly 5 million Medicaid patients found that states with both prescription monitoring and medical cannabis laws saw 19% fewer chronic pain outpatient visits, suggesting cannabis substitution for some conventional treatments.
European analysis shows cannabis-related treatment admissions rose to 37% of all substance treatment entries by 2020, but only 3% of frequent users sought help, indicating a widening treatment gap.
German national data shows cannabis-related medical diagnoses tripled between 2009 and 2021, rising faster than use prevalence, with the biggest increases in middle-aged adults.
Meta-analysis of 120 studies found recreational cannabis use was linked to worse sleep in observational research, but experimental studies showed no effect, suggesting the relationship is more complex than it appears.
Lab study found cannabis extracts containing CBD and CBG were more effective than individual cannabinoids at reducing gut inflammation and restoring intestinal barrier function.
ER survey found cannabis users scored significantly lower on knowledge of negative effects than non-users, with anxiety and pain the top reasons for use.
Prenatal THC increased anxiety in dominant mice offspring but decreased it in submissive ones, revealing that inborn temperament determines how prenatal cannabis exposure affects behavior.
Mouse study found amphetamine disrupted endocannabinoid-dependent brain plasticity through astrocyte CB1 receptors in males only, revealing a sex-specific mechanism in the reward system.
Among 1,922 assault-injured Black men in Baltimore, cannabis was detected most often (42.5%) and was associated with firearm injuries rather than stabbings or blunt force.
Synthetic control analysis of 5 states found recreational cannabis markets increased use prevalence by 11% in teens, 17% in young adults, and 33% in adults 26+, with an 82% increase in new adult users.
Rat study found endocannabinoids and kisspeptin both inhibit hippocampal neurogenesis through TRPV1 receptors, revealing a new regulatory partnership for adult brain cell production.
Review proposes that cannabinoids interact with extracellular vesicles to create a signaling network relevant to neuropsychiatric disorders, with potential for biomarker-guided personalized treatment.
Survey of nearly 17,000 Canadians found majority support for cannabis health warnings and legalization, with regulations broadly accepted even by daily consumers.
Researchers identified a specific group of astrocytes that drive THC-induced cognitive impairment and showed that dampening their overactivity prevents spatial learning deficits in mice.
Randomized study found CBD reduced depression, anxiety, and stress more than THC over 4 weeks in underrepresented groups, with perceived discrimination amplifying the benefit.