Browse more cannabis research, findings, methods, and limitations.
Long-term open-label study of 137 MS patients found Sativex maintained its effects over 434 days without tolerance, and planned 2-week interruption showed no consistent withdrawal syndrome.
Study found cannabis users had lower alertness and slower cognition in work-related testing but did not report more workplace errors, with effects showing "hangover" and fatigue-related patterns.
Small crossover trial found medical cannabis users could distinguish between preparations and preferred highest THC, humidity, and grind size, informing clinical trial product design.
CBD reduced autoimmune diabetes incidence from 86% to 30% in mice by shifting the immune response from harmful Th1 to protective Th2 patterns and reducing pancreatic inflammation.
Survey of 84 medical cannabis users found 65% used cannabis during pregnancy, with 92% of those who used it for morning sickness rating it effective. Fetal safety was not assessed.
Lab study found THC reduced sperm motility by up to 56% and inhibited the acrosome reaction by up to 57% at concentrations matching recreational cannabis use levels.
Large twin study found common genetic factors drive adolescent problem use across tobacco, alcohol, and marijuana, while shared environmental factors drive experimentation but not progression to problems.
National survey of 43,093 Americans identified five drug abuse patterns, with cannabis-only (5.8%) being the most common and mildest, while polysubstance (0.5%) was linked to the most severe psychiatric profiles.
Study of 119 heavy cannabis users found high rates of depression (46%) and suicidality (42%), predicted by parental alcoholism and childhood adversity rather than cannabis or other drug use.
Review of case reports found evidence linking marijuana to heart rhythm problems, heart attacks, and vascular complications, with increasing concern for aging long-term users.
Review finds cannabinoids could modify MS through immune and neuroprotective mechanisms, but dose constraints prevent achieving immunosuppressive benefits clinically. Neuroprotection may be more achievable.
Review of endocannabinoid metabolism identified multiple enzymes for synthesis and degradation of anandamide and 2-AG, positioning these enzymes as drug targets for addiction and other conditions.
Review shows endocannabinoids can inhibit tumor blood vessel formation, cancer cell migration, and metastasis across multiple cancer types, with a favorable safety profile compared to standard chemotherapy.
Researchers mapped the enzymes that break down the brain cannabinoid 2-AG in mice, finding MAGL handles 85% while two other enzymes manage the rest in different cellular locations.
Among 757 first-episode schizophrenia cases, cannabis users and non-users showed essentially the same symptoms, arguing against a distinct "cannabis psychosis."
A clinical trial found that monthly cannabis users responded just as well to combined CBT and medication treatment for anxiety and depression as non-users.
Rats exposed to a synthetic cannabinoid in the womb showed permanent, region-specific changes in their brain's endocannabinoid system as adults.
Review of brain imaging studies found that chronic cannabis users show consistently altered brain function during cognitive tasks, even without clear structural damage.
A randomized trial of 189 MS patients found that a THC/CBD mouth spray significantly reduced spasticity, with 40% of patients achieving meaningful relief.
Review found THC has wide therapeutic potential but psychoactive effects and dependence risk limit clinical use; whole cannabis extracts sometimes outperformed isolated THC.
Review of preclinical evidence found that cannabinoids showed anti-tumor properties against brain cancers in lab and animal studies, including slowing growth and triggering cancer cell death.
CBD reduced heart attack damage by 66% in rats and dramatically lowered inflammation markers, but the effect required a living system and didn't work in isolated hearts.
Patient-oriented Q&A article that briefly covered marijuana for pain alongside topics like fibromyalgia, carpal tunnel, and hypnosis.
CBD activated mast cells in lab tests through an unknown mechanism, behaving opposite to synthetic cannabinoids that suppressed them, suggesting undiscovered cannabinoid receptors exist.
Teen cannabis+tobacco users showed verbal memory deficits and disrupted brain connectivity that only appeared during nicotine withdrawal, suggesting cannabis may damage memory circuits that nicotine temporarily masks.
Regular cannabis users showed lower hippocampal brain activity during memory tasks than non-users but performed just as well, with no structural brain differences detected.
A single CBD dose before allergen exposure significantly suppressed antibody production, immune cell cytokine output, and T-cell proliferation in mice.
Review described how the endocannabinoid system drives reward-seeking in both addiction and obesity, making targeted CB1 modulators promising but challenging drug candidates.
Cannabis extract with CBD enhanced automatic brain responses to auditory changes, while pure THC alone did not, suggesting CBD may protect cognitive processing.
Mutating a single amino acid in the CB1 receptor eliminated binding for some cannabinoids while leaving others unaffected, revealing multiple binding sites on the receptor.
Activated CB1 receptors were routed to degradation via GASP1 in cells and neurons, offering a mechanistic link to receptor down-regulation.
Review found cannabinoids showed promise for managing pain, appetite loss, nausea, and other symptoms in serious illness, with potential to complement and reduce opioid use.
A four-year drug testing program in the Finnish military tested over 2,000 samples and found only one case of illicit drug use (cannabis and amphetamine).
Survey of nearly 2,000 Zambian students found 31% reported suicidal thoughts and 36% had used marijuana, with a modest but significant association between the two.
Sativex reduced neuropathic pain nearly three times more than placebo in 125 patients, with benefits lasting a full year in an extension study without dose escalation.
Year-long study found combined MDMA and cannabis users had sustained immune cell decreases and more infections, with cannabis-only users showing intermediate effects.
Case report of a 30-year-old whose polysubstance use (cannabis, MDMA, cocaine) led to cognitive decline, functional impairment, depression, and a suicide attempt.
Gene-knockout mouse study proved cannabinoids control MS-like spasticity through CB1 receptors, not CB2, meaning therapeutic and psychoactive effects are inherently linked.
Mouse study found THC enhanced MDMA reward at low doses but reduced it at high doses, with both drugs converging on dopamine signaling in the brain's reward center.
Two-year open-label follow-up of 28 MS patients found sustained Sativex pain relief without tolerance or dose escalation, though 25% of all participants dropped out due to side effects.
Review for pharmacists covered medical marijuana's five main therapeutic uses, known drug interactions, adverse effects, and the complex legal landscape as of 2007.
Twin study of 1,088 pairs found that childhood conduct problems contributed a small but significant genetic risk to marijuana use 8 years later, suggesting shared genetic vulnerability.
Review of clinical trials found growing consensus that cannabinoids help at least some MS patients with pain and spasticity, with generally mild side effects compared to alternatives.
Mouse study found CB1 receptor expression correlated with endocannabinoid enzyme expression, suggesting coordinated regulation, while dietary arachidonic acid had no effect on any of these genes.
Mouse study mapped how the uterus creates precise endocannabinoid gradients essential for embryo implantation, with disruption leading to compromised pregnancy outcomes.
Genome-wide scan of high-risk families found overlapping chromosomal regions linked to both alcohol and cannabis dependence, particularly on chromosomes 2 and 10, suggesting shared genetic vulnerability.
Brain imaging of 11 heavy marijuana users who started in adolescence found structural white matter damage in the corpus callosum connecting the prefrontal cortices.
Five-year follow-up of 166 bipolar patients found cannabis use specifically preceded manic episodes, while alcohol preceded depressive episodes, with neither following mood episodes.
Review proposed that the endocannabinoid system could both relieve MS symptoms and slow disease progression, with local endocannabinoid enhancement as a strategy to minimize psychoactive side effects.
Pooled analysis of 430 lung cancer cases from North Africa found cannabis smoking associated with 2.4x higher risk after adjusting for tobacco, with combined tobacco+cannabis use carrying an 18.2x risk.