Browse more cannabis research, findings, methods, and limitations.
The landmark IOM report found therapeutic promise for cannabinoids in pain, nausea, and appetite, recommended against smoking in favor of an inhaler, called for research investment, and found limited gateway and addiction risks.
Over 15 years, cannabis abusers were four times more likely to develop depression including suicidal thoughts. Depression at baseline did not predict future cannabis abuse, arguing against self-medication.
In one of the only controlled studies of suicidal substance abusers, fluoxetine reduced depression, suicidal ideation, alcohol, and marijuana use, with benefits lasting one year.
THCV-COOH, a urinary metabolite unique to natural marijuana, reliably distinguished marijuana use from prescription Marinol use in a controlled crossover study.
The endocannabinoid system is disrupted in Huntington's, Parkinson's, schizophrenia, and tremor, offering both pathological insights and therapeutic targets including agonists, antagonists, and endocannabinoid modulators.
Australian editorial arguing for prosecution exemptions for patients using cannabis medicinally, noting that while cannabinoid drugs were not registered, patient need warranted a compassionate policy response.
Conference report showing whole cannabis extracts outperformed single cannabinoids for spasticity in animal models, while UK clinical trials for pain and multiple sclerosis were underway.
Comprehensive review finding solid evidence for cannabinoids in nausea and appetite, emerging evidence for pain and spasticity, and weak evidence for glaucoma and asthma, while advocating for non-smoked delivery methods.
A review by THC discoverer Raphael Mechoulam tracing cannabinoids from ancient use to modern clinical applications in nausea, appetite, multiple sclerosis, arthritis, and neuroprotection.
A small randomized trial found that single-dose THC (5-10 mg) for Tourette syndrome did not impair cognition across multiple domains, unlike findings from recreational cannabis use studies.
Chronic THC treatment in rats did not produce tolerance to memory impairment or hippocampal acetylcholine reduction, with both effects mediated by CB1 receptors but operating on different timescales.
A synthetic cannabinoid eye drop reduced eye pressure by up to 31% in 8 glaucoma patients who had not responded to conventional treatments, working through CB1 receptors in the eye.
Systematic review of 30 trials finding cannabinoids outperformed conventional antiemetics for chemotherapy nausea (NNT 6) and vomiting (NNT 8), but with notable side effects including dizziness and dysphoria.
Review of European workplace drug testing finding it far less standardized than US programs, with cannabis as the most frequently detected substance and significant gaps in quality control.
Econometric study using cigarette prices as a natural experiment found evidence that smoking leads to cannabis use, but weak evidence that cannabis use leads to harder drugs, challenging gateway theory.
Population-based study of 232 first schizophrenia episodes finding double the rate of substance abuse compared to controls, with cannabis used by 88% of drug abusers and drug use often preceding illness onset.
Animal study showing a compound from passionflower reduced THC tolerance, dependence, and withdrawal symptoms in mice, suggesting potential for cannabis withdrawal treatment.
A 21-year study of 1,265 New Zealand children found cannabis use linked to crime, depression, suicidal behavior, and other drug use, with younger users (14-15) affected more than older users (20-21).
A California compassionate access program found that all 9 glaucoma patients given THC or marijuana discontinued within 9 months due to tolerance and side effects, despite initial pressure reduction.
Twin study of 3,360 male pairs finding that the genetic link between depression and cannabis/alcohol dependence was largely explained by shared genetic risk for antisocial personality disorder.
Comprehensive review mapping how cannabinoids affect different brain regions: memory in the hippocampus, movement and reward in the basal ganglia, appetite in the hypothalamus, with neuroprotective properties.
Review finding cannabis increases heart rate with rapid tolerance development, poses minimal risk for young healthy users but significant risks for people with existing cardiovascular disease.
A nationally representative US twin study found cannabis use in the past year was at least 60% heritable, with identical twins much more similar than fraternal twins or siblings.
Randomized trial in 16 MS patients found neither oral THC nor cannabis extract reduced spasticity, and both worsened patients' overall impression compared to placebo.
Review finding that blocking or removing CB1 receptors enhanced memory performance, suggesting the endocannabinoid system normally constrains memory formation, while also modulating opioid dependence.
First RCT showing THC significantly reduces tics and OCD symptoms in Tourette syndrome, with effects linked to the 11-OH-THC metabolite rather than THC itself.
Review of 9 clinical trials and animal research finding cannabinoids reduced spasticity, pain, tremor, and bladder symptoms in MS, with elevated endocannabinoid levels in spastic conditions.
Electrophysiology study showing cannabinoids strongly inhibited excitatory inputs to the brain's reward center through CB1 receptors, independent of dopamine and opioid systems.
Study discovering endocannabinoids in human reproductive fluids and cannabinoid receptors on sperm, finding that cannabinoid compounds and THC impaired sperm capacitation and fertilizing potential.
Review finding cannabinoids can reduce MS spasticity and pain but questioning their superiority over existing treatments, with too few controlled trials for definitive conclusions.
Review finding that smoking cessation did not increase relapse to other substances and continued smoking actually worsened marijuana treatment outcomes, supporting integrated treatment.
GW Pharmaceuticals developed Sativex and other cannabis medicines, with phase III trials showing significant neuropathic pain reduction in MS, leading to licensing with Bayer AG.
Lancet Neurology review arguing that cannabinoid therapeutic potential extends beyond MS symptoms to neuroprotection, and that the field was only beginning to appreciate the possibilities.
Stopping heavy cannabis use was linked to withdrawal that began within 1–3 days, peaked in Days 2–6, and typically resolved by two weeks.
Comprehensive review cataloging cannabinoid therapeutic potential across MS, Parkinson's, neuroprotection, pain, and appetite, highlighting non-psychoactive cannabinoids as potentially offering benefits without psychoactivity.
Review documenting that cannabis and other drugs of abuse suppress immune function through receptor-mediated mechanisms, increasing infection susceptibility, with implications for HIV/AIDS.
Review comparing cardiovascular effects of five substance classes, finding cannabis posed fewer heart risks than opiates, amphetamines, or alcohol, though cognitive effects were noted.
Comprehensive pharmacokinetics review: inhaled THC peaks in minutes and lasts 2-3 hours; oral THC takes 30-90 minutes and lasts 4-12 hours, with therapeutic applications across pain, nausea, and neuroprotection.
Nature Reviews Cancer paper documenting that cannabinoids inhibited tumor growth in lab and animal studies while being well tolerated, raising the question of anticancer therapeutic potential.
Policy review finding THC moderately effective for nausea, appetite, and pain, comparing medical cannabis approaches across US, UK, Australia, and Canada.
Major Brain journal review finding cannabis cognitive impairments appear reversible with little evidence of brain pathology, and limited evidence for causal psychiatric illness links.
Brain wave study showing chronic cannabis users processed auditory attention differently, with reduced P3 responses to targets and greater effects in early-onset users, undetected by standard tests.
First long-term controlled trial showing THC (up to 10 mg/day) significantly reduced Tourette syndrome tics over 6 weeks in 24 patients with no serious adverse effects.
In anesthetized rats, activating CB1 receptors in the brainstem's ventrolateral medulla increased blood pressure and sympathetic nerve activity while eliminating phrenic nerve discharge. This revealed a novel cannabinoid-cardiorespiratory link.
Survey of 420 MS patients finding 96% aware of cannabis therapeutic potential, 16% using it medicinally with reported improvements in anxiety, spasticity, and chronic pain.
Animal study showing CB1 receptor knockout mice suffered worse neurodegeneration in MS model, while CB1 activation provided neuroprotection, suggesting cannabis could slow MS disease progression.
Study finding cannabis users showed reduced depth inversion illusion scores, a pattern shared with schizophrenia patients, undetected by standard cognitive tests, suggesting subtle visual processing changes.
Comprehensive review documenting reliable THC self-administration in monkeys and major cannabinoid-opioid-dopamine interactions underlying reward and dependence.
Review proposing cannabis may be a gateway to tobacco rather than the reverse, with university student research suggesting cigarette initiation often followed marijuana use.
Controlled trial showing sublingual cannabis extracts (THC and CBD) significantly improved pain and bladder symptoms in 24 patients with treatment-resistant neurological conditions.