Browse more cannabis research, findings, methods, and limitations.
Novel peripherally restricted CB1 antagonist TM38837 was 10x less fear-promoting than rimonabant in mice while maintaining anti-obesity efficacy in previous studies.
Longitudinal study of 500 adolescents found marijuana use caused BDNF alterations (not vice versa), with age of onset influencing the pattern of neurotrophin changes.
Systematic review of 35 CBD clinical studies finds effective doses from 1-50 mg/kg/day across 13 conditions, with epilepsy best supported and negative results potentially due to underdosing.
Adolescent THC caused premature dendritic pruning and altered gene networks in rat PFC neurons, with dysregulated networks overlapping schizophrenia-associated pathways.
Study of 98 Tourette syndrome patients found 85% reported tic improvement with cannabis-based medicines, with patients preferring THC-rich medicinal cannabis over pharmaceutical alternatives.
JAMA Psychiatry meta-analysis of 18 studies finds elevated anandamide in CSF and blood of schizophrenia patients, highest early in illness and inversely related to symptom severity.
Phase II trial of CBD gelatin bead formulation (PTL-101) showed 82% seizure reduction in children with treatment-resistant epilepsy, with 56% achieving 50%+ improvement.
Review of cannabinoid-AED interactions shows enhanced seizure protection but also neurotoxicity with non-selective agonists; selective CB1 agonists may offer safer combinations.
Rats showed more NREM sleep only for 1 hour after the highest vaporized THC dose, only in the light phase.
Colorado study found edible cannabis accounted for 0.32% of THC sales but 10.7% of cannabis ER visits, with higher rates of psychiatric, intoxication, and cardiovascular events.
Study of 4,028 adults with congenital heart disease across 15 countries found cannabis-only use had negligible impact, while cannabis-tobacco co-use moderately worsened mental health.
Population study of 3,826 adolescents found cannabis caused lasting cognitive deficits in inhibitory control and working memory, with effects independent of and more pronounced than alcohol.
Phase 1 trial shows CBD triples active clobazam metabolite levels, modestly increases stiripentol, and does not affect valproate, guiding dose adjustments for combination therapy.
Review of cannabinoids for chemotherapy nausea highlights CBD's non-psychoactive antiemetic potential through serotonin inhibition, alongside THC's established efficacy.
Chronic A2A receptor antagonism (istradefylline) reversed cannabinoid-induced memory deficits and partially rescued hippocampal synaptic plasticity in rats.
Mouse study found CBD did not prevent THC cognitive impairment or withdrawal, but CBD alone showed anxiolytic effects without cognitive harm or dependence.
Review maps how CB1 receptor activation drives hepatic insulin resistance and obesity, highlighting peripheral-only CB1 blockade as a promising therapeutic approach.
Study of 17 cannabis strains found terpenoids enhanced cannabinoid anti-cancer activity only when naturally co-occurring in the same strain, supporting strain-specific entourage effects.
A single session of vaporized THC suppressed gamma-frequency brain activity in multiple rat brain regions, and most effects were still present a week later.
The first cannabis receptor blocker worked for obesity and quitting smoking but caused depression and suicidal thoughts. Researchers are now developing safer alternatives.
Three young adults with chronic cannabis use and cannabinoid hyperemesis syndrome died, with CHS determined as the cause of death in two cases.
Two longitudinal studies found that parental cannabis use was associated with higher rates of cannabis use in their children, from adolescence through young adulthood.
Cocaine users who also used cannabis heavily had worse cognitive performance and no reduction in relapse compared to cocaine-only users.
In 404 first-episode psychosis patients, tobacco, alcohol, and cannabis use each predicted worse treatment outcomes over two years, with tobacco linked to the most negative effects.
Systematic review of cannabis for PTSD through 2019 found promising signals for nabilone and nightmares, but most evidence remained low-quality and the broader case unproven.
CBD reversed memory and social deficits in female rats from a schizophrenia model, but reduced social behavior in healthy rats.
In over 1,000 people, testing positive for THC was linked to worse working memory and altered brain activity, but past cannabis use history was not.
THC impaired standard cognitive tests but brief phone-based equivalents mostly failed to detect the impairment, casting doubt on phone apps as cannabis sobriety tests.
In a large Asian multi-country study, schizophrenia patients with lifetime cannabis use had higher rates of aggressive behavior and were more likely to receive long-acting injectable antipsychotics.
A patient with cannabinoid hyperemesis syndrome responded to aprepitant after standard anti-nausea drugs failed.
A systematic review found that cannabis may reduce sperm count, motility, and fertilizing capacity, though effects on testosterone remain unclear.
A review maps cannabis-related psychosis through DSM-5 categories, showing a continuum from intoxication to cannabis-induced psychotic disorder to schizophrenia.
Overexpressing a cannabinoid receptor regulatory protein (CNRIP1) in rat brains produced schizophrenia-like behavioral and dopamine system changes.
CHS causes severe cyclic vomiting in chronic cannabis users, is uniquely relieved by hot showers and capsaicin, and resolves with cessation.
The 2019 EVALI outbreak caused 805 lung injury cases and 12 deaths. Over three-quarters of patients with substance data reported using THC vaping products.
A Danish study of over 3 million people found that schizophrenia significantly increases the risk of subsequently developing substance abuse, with cannabis showing the highest risk.
Cannabis shows promise in animal IBD models but has not demonstrated anti-inflammatory efficacy in human trials. It may help manage symptoms like pain and nausea.
A patient with Tourette syndrome resistant to antipsychotics and pure THC showed rapid improvement when treated with a THC + CBD combination.
In 29 children with severe epilepsy, purified CBD reduced seizures by 50% or more in 38% of patients, with mild side effects and no worsening in any patient.
Prenatal cannabis exposure alters dopamine, serotonin, GABA, and other neurotransmitter systems in offspring, with effects that vary by brain region and sex.
A meta-analysis found cannabis users had 69% ED prevalence versus 35% in non-users, with nearly four times the odds, though study heterogeneity was high.
CBD is theoretically promising for autism spectrum disorder, but at the time of this review, no convincing evidence of efficacy or safety in ASD patients existed.
Indoor cannabis smoking was associated with higher air particle levels and a non-significant trend toward worse child health outcomes in homes where tobacco was already smoked.
A review of 72 systematic reviews on medical cannabis found mostly inconclusive results, frequent mild harms, and overwhelmingly low-quality evidence.
A single dose of CBD altered brain activity in regions implicated in autism (cerebellum, fusiform gyrus) in men with ASD but not in neurotypical controls.
CBD modulated brain glutamate and GABA levels, but in opposite directions for people with autism versus neurotypical controls.
Cannabis components inhibit multiple liver enzymes responsible for metabolizing common medications, creating potential for significant drug interactions.
Cannabis and turmeric show potential for IBD symptom management, but neither has been compared to standard treatment and should not be used as a substitute.
Young adults with both marijuana use and depression had worse verbal memory and thinner cortex than those with either condition alone, suggesting additive harm.
Medical cannabis states had 24-44% lower opioid prescription rates in adults under 55, but recreational cannabis and decriminalization laws showed no effect.