Browse more cannabis research, findings, methods, and limitations.
Survey of 239 young LA cannabis users found CBD-dominant product users were more medically motivated and reported more pain, but also used more illicit drugs, especially psilocybin.
Chart review of 45 gynecologic cancer patients on medical marijuana found 71% reported symptom improvement, with nausea responding much better (>70%) than pain (36%).
Survey of 404 Austrian students found medical students struggled to tell CBD from THC apart and were more skeptical of medical cannabis than non-medical students, despite more university education on the topic.
Study of 863 Spanish adolescents found girls had higher mental health-substance use comorbidity, with depression predicting cannabis use disorder and obsessive-compulsive symptoms predicting alcohol use disorder.
Survey of 1,000 Canadian rheumatology patients found 24% of fibromyalgia patients had tried medical cannabis, with 61% continuing use and reporting 7/10 symptom relief.
Monthly surveys of 761 young adults found marijuana use peaked in April and December, while alcohol peaked in summer, October, and December, with patterns varying by college status.
Study of 1,108 college students found those who mixed prescription stimulants with alcohol or marijuana had the heaviest substance use, most consequences, and used marijuana to alter other drug effects.
CBD is approved for three epilepsy syndromes based on multiple RCTs, but its interaction with clobazam (boosting active metabolite levels) makes it difficult to isolate CBD's independent antiseizure contribution.
Study of 318 IVF follicular fluid samples found cannabis exposure altered cannabinoid receptor and DNA methylation enzyme expression in granulosa cells, with cannabis detection tripling after Canadian legalization.
Systematic review found CBD effective in rodent MS models but clinical results in humans were limited and usually negative, possibly because doses tested were too low.
Study of 5,792 high schoolers found earlier substance use predicted emotional detachment from parents, which in turn predicted progression to illicit drugs like cocaine and hallucinogens.
Pilot study of 17 burning mouth syndrome patients found cannabis oil improved pain, anxiety, and depression over 4 weeks, with benefits lasting through 24-week follow-up.
Analysis of 71,870 Oregon 11th graders found counties with the most marijuana and alcohol retail outlets had significant increases in adolescent co-use after legalization, mediated by changes in beliefs about availability and risk.
CBD reversed behavioral symptoms and molecular brain changes during spontaneous cocaine withdrawal in mice, normalizing dopamine and cannabinoid receptor gene expression.
Survey of nearly 3,000 Czech and Slovak university students found tobacco and cannabis use both correlated with alcohol use disorders, with males at higher risk, during early COVID-19.
Among 3,426 women with pelvic pain, cannabis use jumped from 13% to 22% after Canadian legalization, with newer users being more educated and taking fewer daily opioids.
Mouse study found the omega-3 endocannabinoid DHEA was more potent than DHA in raising seizure thresholds, acting through CB1 receptors, while the EPA-derived EPEA had no effect.
Qualitative study found mental health professionals who use cannabis recognized psychological risks but may underestimate physical health harms, suggesting need for professional education.
Interviews with 10 parents revealed families pursued medical cannabis for children with cancer or epilepsy out of desperation, relying on social media and peers rather than healthcare providers for information.
Study of 437 homeless adults found cannabis use before age 15 was linked to substance-induced psychosis while use after 15 was linked to schizophrenia, with corresponding brain differences.
Review of 30 studies found CBD interacts with at least 15 anti-seizure medications through pharmacokinetic mechanisms and 3 through pharmacodynamic mechanisms, primarily via the cytochrome P450 system.
Survey of 401 adults in a California pediatric ER found 14.5% had cannabis at home, but fewer than half stored it locked and hidden, and 45% received no storage guidance.
Adolescent cannabinoid exposure in mice reduced cocaine reward in adulthood and increased a DNA methylation enzyme in the prefrontal cortex, without affecting anxiety or depression.
Stabilized CBDa hemp extracts showed seizure protection comparable to CBD in rats, with the multi-cannabinoid extract outperforming purified CBDa, supporting the entourage effect.
Daily diary study of 62 cannabis users found those with more ADHD symptoms experienced more daily cannabis consequences, with boredom and sleep motives increasing problems further.
Rat study found CB1 and CB2 receptors in a key anxiety brain region (BNST) have opposite effects: blocking CB1 reduced anxiety while blocking CB2 increased it.
Study of 284 first-episode psychosis patients found tobacco-only users had a distinct clinical profile, while adding cannabis was linked to 2.5 years earlier onset and more hallucinations and disorganized thinking.
Experiment with 45,378 people found plain packaging reduced cannabis appeal while health warnings increased perceived harm, with specific Canadian-style warnings outperforming generic US warnings.
Analysis of 287,624 US adults with children found cannabis use was 28% higher in recreational legalization states and 12% higher in medical-only states compared to non-legal states.
Mouse model of Tourette syndrome found THC reduced some tic-like behaviors but caused catalepsy, while CBD had no benefit in juveniles and increased head twitching in both age groups.
Daily tracking of 211 adults found opioid use was twice as likely on days they also used cannabis, regardless of pain, contradicting the cannabis-as-opioid-substitute hypothesis.
Review found cannabis smoking causes bronchitis and increases airway resistance but does not clearly cause COPD, emphysema, or lung cancer, a pattern distinctly different from tobacco.
Dual endocannabinoid enzyme inhibition reduced migraine-like pain and CGRP levels in rats through CB1 receptors, affecting both central and peripheral inflammatory markers.
Rat study found chronic morphine significantly increased CB2 cannabinoid receptor expression on spinal neurons, more than nerve injury alone, suggesting a mechanism for opioid-cannabinoid treatment synergy.
Review found THC may increase heart attack risk through sympathetic activation and vascular dysfunction, while CBD shows preclinical cardioprotective effects, creating a complex risk profile.
Meta-analysis of 10,873 rheumatology patients found 40% had used cannabis and 15% were current users, with significant pain reduction among users, especially in fibromyalgia.
Analysis of 6 million COPD hospitalizations found cannabis users had 37.6% lower odds of in-hospital death and 11.8% lower odds of pneumonia compared to non-users.
Systematic review found THC and CBD have opposite brain effects, with THC increasing and CBD decreasing activation, particularly in regions linked to psychosis.
Meta-analysis of 714 patients across 4 RCTs found CBD reduced seizures by about 30% in Dravet and Lennox-Gastaut syndromes, with 37-44% reduction when combined with clobazam.
Survey of 319 rheumatology patients found self-reported pain reductions of 57-83% and sleep improvements of 71-87% with medical cannabis, with neuropathic pain patients reporting the greatest benefit.
Small study of 16 patients found medical cannabis use significantly increased oral Lactobacillus levels within one week, while saliva flow and pH remained stable.
Study found that first-episode schizophrenia patients with a history of cannabis use performed better on cognitive tests, especially visual memory, than non-using patients.
Policy review found that cannabis product labels in regulated markets often fail to help consumers understand THC dose, and proposed five principles for more effective labeling.
National survey of 18,794 older adults found perceived risk of regular cannabis use dropped nearly 19% between 2015-2019, with the steepest declines among those with chronic diseases.
Analysis of 281,650 young adults found cannabis use disorder was associated with higher suicidality regardless of depression, with women showing significantly stronger associations than men.
Study of 599 college students found that perceiving marijuana as risky was linked to lower use, with the association being strongest among younger students.
Retrospective study of 722 IVF patients found no significant differences in implantation, pregnancy, or embryo quality between cannabis users and non-users.
Lab study found THC and THCA caused DNA damage in E. coli bacteria while other cannabinoids caused different types of cellular stress, with mixtures producing distinct patterns from individual compounds.
Twin study of 436 young adults found alcohol misuse was associated with thinner cortex in cognitive control brain regions, reflecting both genetic predisposition and direct exposure. Cannabis showed no such effects.
Genomic analysis found significant genetic overlap between cannabis use disorder vulnerability and COVID-19 hospitalization risk, independent of tobacco, alcohol, or respiratory disease genetics.