Browse more cannabis research, findings, methods, and limitations.
Twin study of 2,793 young adults finding the cannabis-psychosis link is explained by shared genetics (55% correlation) plus a direct effect from cannabis use disorder to psychotic experiences, not the reverse.
Controlled study showing oral cannabis caused 6.4x higher impairment odds on sobriety tests in occasional users, with tolerance in frequent users, highlighting the delayed impairment risk of edibles.
Review of randomized trials of plant-based cannabis (excluding synthetics) for psychiatric and neurologic conditions finding limited evidence across conditions, highlighting the gap between policy approval and clinical evidence.
Survey of 417 family physicians finding 92% viewed marijuana as unsafe in pregnancy but only 63% consistently screened for it, with only 18% screening for all substances.
Systematic review finding few tested treatments for IBD abdominal pain, with relaxation/CBT showing the most consistent benefit and one controlled cannabis trial showing promise.
Review of CBD for treatment-resistant epilepsy showing Phase 3 RCT evidence of efficacy for Dravet and Lennox-Gastaut syndromes, while highlighting the gap between pharmaceutical CBD and unvalidated dispensary products.
Review of how the endocannabinoid system controls immunity, finding widespread expression in immune cells with generally immunosuppressive effects that create both therapeutic opportunities and safety considerations.
Longitudinal study of 711 people showing cannabis use at 17 led to drug-using friendships at 22, which predicted starting cocaine, meth, or opiates by 27, supporting a social rather than pharmacological gateway mechanism.
Mouse study showing MAGL inhibition (boosting 2-AG) produces cannabis-like subjective effects through CB1 receptors, while FAAH inhibition (boosting anandamide) does not, revealing MAGL as a "brake" preventing endocannabinoid intoxication.
Animal study found that both caffeine and cannabis altered neurotransmitter and enzyme levels in juvenile rat brains, with their combination producing amplified metabolic effects.
Mouse study found that endocannabinoid levels in the uterus fluctuate across the reproductive cycle, and cannabinoid receptor activation selectively reduces spontaneous uterine contractions.
Small observational study found CBD-rich hemp oil improved physical functioning, vitality, and pain in young women with chronic symptoms after HPV vaccination, though one-third of participants dropped out.
Review examining arguments for (pressure reduction, neuroprotection) and against (short duration, side effects, delivery challenges) using cannabinoids to treat glaucoma.
Review arguing that cannabis and stimulant drugs damage well-being through the same core mechanism: cyclical mood disruptions that chronically stress the body's hormonal and neurological systems.
Case-control study found that adolescents with first-episode psychosis and a family history of psychosis actually had milder positive symptoms at onset, challenging assumptions about genetic risk.
Mouse study found that boosting the endocannabinoid 2-AG through MAGL inhibition protected dopamine neurons in a Parkinson's model, while boosting anandamide through FAAH inhibition did not.
Survey of 158 California budtenders found that formally trained budtenders were more experienced and digitally connected but less likely to prioritize patient-centered medical decision-making.
Large survey of nearly 39,000 Asian adolescents found cannabis use under 1%, with cigarette smoking the only universal predictor across all five countries studied.
Review of nabilone, a synthetic cannabinoid antiemetic that offers a unique mechanism for treating chemotherapy-induced nausea, particularly the delayed form that other drugs fail to control.
Review marking a turning point: three controlled trials confirmed CBD reduces seizures in Dravet and Lennox-Gastaut syndromes, but a drug interaction with clobazam complicates interpretation of how much benefit is directly from CBD.
Case report of cannabinoid hyperemesis syndrome, a condition in heavy daily cannabis users featuring cyclical vomiting relieved only by hot showers or stopping cannabis.
Rat study found that locally administered CBD reduced osteoarthritis pain and, when given early, prevented pain development and protected joint nerves from damage.
Case report of a chronic cannabis user who developed both cannabinoid hyperemesis syndrome and coronary vasospasm causing a heart attack, suggesting cardiac evaluation in CHS patients with chest pain.
Survey of 1,513 medical cannabis patients found over 75% reduced opioid use and 65-72% reduced sleep and anxiety medications, though their primary care doctors often did not know.
Survey of 984 dispensary members found patients rated medical cannabis 74.6% effective for their conditions, with cost, side effects, and stigma as the main drawbacks.
Qualitative study of 32 young adults in Colorado found they evaluate cannabis and tobacco risks through five lenses: combustion, potency, chemicals, addiction type, and information sources.
Prospective study found that opioid-dependent patients who also used synthetic cannabinoids experienced significantly longer withdrawal and craving during detoxification.
Lab and animal study found that the CB1 receptor blocker rimonabant inhibited a major cancer-promoting pathway and reduced colon cancer tumor growth in mice.
Mouse study demonstrated that a CB1 receptor antagonist rapidly reversed synthetic cannabinoid intoxication effects, supporting the concept of a cannabinoid overdose antidote.
Small prospective study found significant verbal memory improvement (d = 1.07) in schizophrenia patients who achieved 28 days of cannabis abstinence.
Review of herbal medicine use in elderly IBD patients identifies cannabis among many supplements with potential drug-herb interactions, emphasizing the need for provider awareness.
Survey of nearly 2,900 medical cannabis patients found 97% reported being able to reduce opioid use with cannabis, and 81% found cannabis alone more effective than the combination.
Study found cannabis had opposite effects on brain signal filtering in schizophrenia (improved) versus healthy people (impaired), suggesting fundamental endocannabinoid system differences.
Mouse study found that guineensine from black pepper produced potent anti-inflammatory and pain-relieving effects by blocking endocannabinoid reuptake, with effects partially mediated through CB1 receptors.
Hypothesis paper proposing that CHS results from chronic cannabis disruption of the HPA stress axis and sympathetic nervous system, causing endocannabinoid dysfunction and loss of autonomic balance.
Systematic review of 63 studies (205 patients) found benzodiazepines, haloperidol, and capsaicin most frequently effective for acute CHS, with hot showers universally helpful.
Analysis of 4,294 fatal crashes in California found cannabis-positive drivers were 1.89x more likely to be crash-responsible at zero BAC and 3.42x more likely at very low BAC.
Methodological analysis explaining why two studies using the same crash databases reached opposite conclusions about marijuana and fatal accident risk, highlighting critical database limitations.
Comprehensive review finding that CBD and CBDV consistently reduce seizures in animal models, while THC-like CB1 agonists show complex, context-dependent effects that can be either anti- or pro-seizure.
Rat study found CBD disrupted fear memory consolidation when injected into the prefrontal cortex 5 hours (but not immediately) after fear learning, reducing dopamine activity and memory gene expression.
Major pharmacology review arguing that cannabis's therapeutic potential involves far more than THC and CBD, with terpenes and lesser-known compounds providing meaningful synergistic pharmacological activity.
Mouse study found that memory problems during nicotine withdrawal are driven by increased endocannabinoid (2-AG) signaling through CB1 receptors on inhibitory neurons, with associated loss of dendritic spines.
National survey found current marijuana users had double the tobacco use (69% vs. 28%) and one-third the sustained cessation rate (22% vs. 66%) compared to never-marijuana users.
Rat study found synthetic cannabinoids lower temperature through CB1 receptors but raise blood pressure through a separate sympathetic nervous system mechanism unrelated to cannabinoid receptors.
Review of cannabis withdrawal neurobiology finding CB1 receptor downregulation drives withdrawal symptoms, recovery occurs with abstinence, and women may experience faster and more severe symptoms.
Survey of 6,089 Hawaiian teens found e-cigarette use independently associated with asthma (aOR 1.48), while marijuana and cigarette use were not significant after controlling for e-cigarettes.
Australian study found cannabis cautioning cost half as much as arrest ($388 vs. $733) with no difference in subsequent cannabis use, supporting diversion over criminalization.
Case series of 8 patients with marijuana-associated heart attacks, average age 40, with half having minimal or no traditional cardiovascular risk factors.
Among 302 adults entering cannabis treatment, women had significantly more severe withdrawal, more psychiatric disorders, and more pain than men despite identical cannabis use patterns.
Longitudinal study of 2,539 teens found neighborhood drug problems predicted marijuana use, but personal resistance confidence and avoiding drug-using peers buffered these effects.