Browse more cannabis research, findings, methods, and limitations.
Review finds neither per se THC blood limits nor field sobriety tests reliably detect cannabis-impaired driving, arguing for general impairment detection strategies instead of substance-specific approaches.
New Zealand pharmacologists argue that medicinal cannabis is not a single entity and all cannabis products should meet the same quality and evidence standards as other pharmaceutical medicines.
Meta-analysis of 23,317 individuals found adolescent cannabis use linked to 37% higher depression risk and 3.46x higher suicide attempt risk in young adulthood, even after accounting for pre-existing mental health.
Mouse study reveals a peripheral CB1 blocker reduces alcohol drinking by suppressing active ghrelin production in the stomach, working through gut-to-brain vagal nerve signaling without entering the brain.
Experiment with 27,000+ participants found plain packaging and health warnings reduce cannabis product appeal, with edible gummies being the most youth-appealing product type.
Systematic review comparing adolescent and adult cannabis users suggests teens may be more vulnerable to executive function deficits, especially heavy users, but these effects may reverse with sustained abstinence.
Washington State data shows marijuana use declined among younger teens after legalization but increased among working 12th graders relative to non-working peers, especially those working more hours.
Clinical review for psychiatrists finds synthetic cannabinoids cause faster dependence, worse psychiatric symptoms, more dangerous withdrawal, and physical effects including seizures and death compared to natural cannabis.
Study of 104 PrEP-using gay men over 9,532 days found marijuana use and heavy drinking did not affect HIV prevention pill adherence, while club drugs increased missed doses by 55-60%.
Lab and mouse study shows CBD, CBN, and THC all suppress immune defenses against three major gum disease bacteria through a CB2/PI3K pathway, revealing why cannabis use increases periodontal disease risk.
Largest MS cannabis survey finds 49% of 2,009 Danish patients have used cannabis, mostly illegally, reporting high efficacy for pain and spasticity with mild side effects, while 44% of non-users would consider it if legalized.
Mouse study reveals cannabinoid receptor activation raises seizure thresholds partly by reducing hippocampal ATP and opening ATP-sensitive potassium channels, adding a new mechanism to cannabinoid anticonvulsant effects.
Review finds cannabis shows anti-inflammatory potential for IBD, but evidence is insufficient to recommend use in pediatric patients, calling for pediatric-specific safety and efficacy studies.
Lancet review finds cannabis legalization associated with increased use and road crash concerns, warns commercial cannabis industries may resist effective regulation like alcohol and tobacco, and outlines harm-minimizing policy approaches.
Canadian study of 43,466 people found women who use cannabis regularly experience significantly more psychological distress and suicidal thoughts than men who use at the same frequency.
Review finds the cannabis-schizophrenia causal hypothesis remains unproven after decades of research, with three competing explanations and significant gaps in social, cultural, and non-Western evidence.
Analysis of 42 years of US fatal crash data finds little evidence that April 20th cannabis celebrations increase drivers involved in fatal crashes when compared against appropriate control periods.
Rat study shows boosting endocannabinoids in the hippocampus prevented both the immediate cardiovascular stress response and delayed anxiety 24 hours later, both through CB1 receptor signaling.
Review of cyclic vomiting syndrome highlights its overlap with cannabinoid hyperemesis syndrome and connections to migraine and mitochondrial disorders, proposing a multicenter registry for future research.
Study of 401 at-risk teens found 74% maintained low cannabis use, with boys more likely to show chronic or escalating patterns and conduct disorder showing the strongest bidirectional link to problematic use.
Rat study shows the neutral CB1 antagonist AM4113 reduces heroin self-administration without the depression-like side effects that derailed rimonabant, pointing toward a safer cannabinoid-based opioid addiction treatment.
Case report of CBD use for chronic pain and mood disorder in neurofibromatosis type 1, suggesting potential but requiring controlled trials for validation.
Review for fetal/neonatal specialists covers how the endocannabinoid system guides brain development and why exogenous cannabinoids during pregnancy, infancy, or adolescence can disrupt normal neural development.
Spain's national roadside testing of 180,000 drivers found THC in 80% of drug-positive tests, with half of THC-positive drivers also positive for cocaine or amphetamines, especially at lower THC levels.
Controlled study shows varenicline doubled tobacco abstinence rates in cannabis co-users (46% vs 24%), while nabilone eased cannabis withdrawal, with tobacco-related variables predicting cannabis relapse.
Systematic review of 14 RCTs (1,629 participants) finds cannabis-based medicines improved symptoms across multiple mental disorders as adjuncts but achieved no remissions, with larger trials needed.
Study of young IBD patients found 15 cannabis oil users had similar clinical profiles to 67 non-users but reported perceived benefits for sleep, nausea, and appetite, with most also using other cannabis forms.
Small pilot study of guanfacine for cannabis withdrawal in 7 volunteers found no significant effects on withdrawal or craving, with trends toward improved mood that may warrant larger investigation.
Case of cannabis hyperemesis in a patient with terminal ALS shows atypical presentation without hot bath behavior, and suggests dose reduction rather than cessation may manage symptoms in palliative care.
Rat study identifies ERK1-2 phosphorylation in the hippocampus as the molecular mechanism by which THC causes psychosis-like dopamine dysregulation and CBD reverses it.
Five-year case report of Finnish adult ADHD patient who found medical cannabis (THC-dominant plus THC/CBD blend) more effective than Ritalin for emotional regulation, anger, and concentration.
Review finds cannabis science dangerously behind the legalization reality, with 63% of Americans accessing medicinal cannabis markets while research barriers create critical knowledge gaps.
Clinical review for neurologists notes about half of MS patients use cannabis medicinally, while practitioners lack prescribing guidance and pharmaceutical-grade products remain restricted.
Mouse study shows paternal cannabinoid (CB2) exposure alters sperm DNA methylation and reduces offspring growth through epigenetic changes transmitted in sperm to the placenta.
Mouse study maps synthetic cannabinoid 5F-AMB's effects: anxiety reduction and memory impairment via CB1 receptors in different brain regions, with severe locomotor impairment at systemic doses.
Rat study shows adolescent cannabinoid exposure produces lasting reductions in prefrontal cortex activity during reward processing in adulthood, suggesting disrupted brain maturation.
First systematic review of cannabis effects on the endocannabinoid system finds chronic use downregulates CB1 receptors in a pattern that may overlap with changes observed in psychosis.
Prospective neuroimaging studies find recency, frequency, and age of onset of teen cannabis use predict brain health outcomes, with preexisting brain differences also contributing to vulnerability.
Rat study shows CBD reduces diabetic nerve pain through spinal cord serotonin 5-HT1A receptors rather than cannabinoid receptors, with chronic treatment restoring depleted serotonin levels.
Study of 1,661 Australian teens found 10% used multiple substances, with depression, conduct problems, and school environment as the strongest predictors, suggesting prevention should target mental health.
Mouse study shows adolescent THC only caused lasting memory impairment when combined with genetic vulnerability in astrocytes (support cells), operating through an inflammatory pathway blockable by a COX-2 inhibitor.
First US adolescent fMRI cannabis cue study shows 41 cannabis-using youth had heightened brain activation to cannabis images in reward and attention regions.
Substudy of 37 cannabis-using youth found approach avoidance training that reduced cannabis use in a larger trial did not significantly change brain cue reactivity on fMRI, with only trend-level effects.
Case report of a 26-year-old male who had a heart attack and heart failure after a cannabis smoking binge, adding to rare but concerning documented cardiovascular events in young cannabis users.
Mouse study finds cannabinoids reduce a brain appetite signal (nesfatin-1) through both CB1 and CB2 receptors, with CB2 activation separately linked to increased insulin resistance.
Motivational therapy sessions with 56 frequent cannabis-using teens found emotional coping was the main use driver, with most identifying education, career, and family as values they saw cannabis use conflicting with.
Oregon survey of 39 cannabis-using epilepsy patients found 87% used for seizures and 82% said it helped, but only 2 could specify their dose, highlighting the gap between self-medication and medical-grade use.
CUMYL-4CN-BINACA caused seizures in mice at the lowest dose reported for any synthetic cannabinoid, acting through CB1 receptors.
Review of evidence on cannabis as a potential substitute or complement to opioids for pain management, finding promising but preliminary support.
Case series of four CHS patients who failed standard antiemetics but responded to benzodiazepines.