Browse more cannabis research, findings, methods, and limitations.
Review of animal studies shows the endocannabinoid system modulates both physical and emotional opiate withdrawal through distinct brain regions, with CB1 effects varying by location.
Study of 686 drug-using ED patients found cannabis-only users had lower severity than other drug users, but 19-29% still had problematic use, especially daily users who showed lower self-efficacy.
Review finds cannabis smoke causes bronchitis, may lead to pneumonia and airway obstruction, and poses a potential but inconclusive lung cancer risk with long-term heavy use.
Adolescent THC exposure produced lasting memory deficits and psychotic-like behaviors in male rats, driven by glutamate signaling disruption and neuroinflammation specifically in the hippocampus.
Natural brain peptides targeting the CB1 cannabinoid receptor had opposite effects on memory depending on brain health: blocking CB1 helped healthy mice, while activating it restored memory in an Alzheimer's model.
Researchers designed CB1 receptor blockers that cannot enter the brain, aiming to treat obesity through the cannabinoid system without causing psychiatric side effects.
Cannabis-related emergency room visits in the US increased significantly from 2004 to 2011, with the steepest rises among adolescents and disproportionate representation of Black Americans.
A 25-year cohort study found childhood conduct problems and adolescent attention difficulties independently predicted problematic cannabis use by age 25.
Twelve elderly people accidentally ate marijuana cookies at a hemp food workshop, sending two to intensive care, though all recovered fully.
Review showing cannabinoids reduce inflammation through mechanisms different from NSAIDs, with several compounds in clinical development for chronic inflammatory and fibrotic diseases.
The endocannabinoid anandamide promotes immune tolerance in the gut via CB2 receptors, and capsaicin triggers the same pathway, protecting mice from type 1 diabetes.
In identical twin pairs, the twin who used cannabis frequently was about twice as likely to have depression and 2.5 times as likely to report suicidal thoughts, even after controlling for shared genetics.
Suicide attempts predicted later development of substance dependence (including cannabis), but early substance use showed limited evidence of predicting future suicidal behavior.
Adolescent cannabinoid exposure in mice altered cocaine withdrawal in adulthood, preventing anxiety but worsening depressive symptoms during cocaine cessation.
Nationally representative study found no significant difference in self-reported eyesight quality between heavy marijuana users and light/non-users.
College students who viewed young adulthood as a time for experimentation were more likely to use marijuana and binge drink, while those focused on identity exploration used less marijuana.
Rat pups born to mothers on high-fat diets developed early obesity with sex-specific alterations in cannabinoid receptor expression across different fat tissue types.
ACOG's 2017 committee opinion formally recommended against cannabis use during pregnancy and lactation based on neurodevelopment concerns and insufficient safety data.
A variant in the cannabinoid receptor gene CNR1 was linked to more frequent cannabis use at age 18, but the genetic effect did not change the trajectory of use over the following six years.
Controlled study showing oral CBD up to 800mg produced no abuse-related effects in frequent marijuana users, supporting CBD's favorable safety profile.
Review of cannabis and sleep research through 2017 found CBD promising for insomnia, THC mixed (faster onset but worse quality), and the whole field still in its infancy.
A cannabinoid-inspired compound (VSN16R) controlled spasticity in MS mice by opening neuronal potassium channels rather than through cannabinoid receptors, achieving a 1,000-fold therapeutic window without sedation.
Survey of 47 Parkinson's patients found large self-reported improvements in falls, pain, and tremor with medical cannabis, but 17% experienced confusion or hallucinations.
Protracted withdrawal from THC, morphine, nicotine, and alcohol produced similar behavioral and molecular patterns in mice, while cocaine withdrawal was strikingly opposite.
CB1 receptors in the nucleus accumbens were essential for learning relief associations in rats but not for recalling them, revealing a role for cannabinoid signaling in emotional memory formation.
THC-induced anxiety in healthy men was directly correlated with CB1 receptor density in the amygdala, providing the first human evidence linking individual brain chemistry to vulnerability to cannabis anxiety.
Review of five clinical studies found some evidence that THC and CBD formulations reduce cancer pain, with effective doses as low as 2.7mg THC plus 2.5mg CBD, but the evidence base remains small.
Chronic cannabis users showed weakened brain connections between motivation centers and both frontal and visual processing areas, but these changes began normalizing after one month of abstinence.
Review finding that cannabinoid hyperemesis and cyclic vomiting syndromes are nearly identical in presentation, with complete symptom resolution after quitting cannabis being the only reliable differentiator.
Comprehensive review establishing cannabis withdrawal as a neurobiologically grounded syndrome with a 4-week CB1 receptor recovery timeline, gender differences in severity, and limited but promising pharmacological treatments.
Prospective study of young Mexicans found cannabis use before age 15 was associated with nearly 4x risk of suicidal ideation and 5x risk of suicide attempt over eight years of follow-up.
In a 20-year cohort study, adolescent self-harm independently predicted weekly cannabis use at age 35, the only outcome that survived adjustment for adolescent mental health and behavior problems.
Review identifying the endocannabinoid system as a promising pharmacological target for the complex, multi-mechanism pain of endometriosis.
Survey of 114 Colorado providers found frequent marijuana screening but low confidence discussing specific health risks, highlighting gaps in medical education around cannabis legalization.
Among underage drinkers in an ER sample, marijuana use more than doubled the odds of driving after drinking for females and significantly increased risk for males.
Daily cannabis use predicted suicidal ideation through feeling like a burden to others, but only when combined with feeling disconnected, supporting a psychological theory of cannabis-related suicide risk.
Low-level pesticide exposure during development inhibited endocannabinoid enzymes in the liver, spleen, and brain of rat pups at doses below traditional neurotoxicity thresholds.
A letter discussing emerging treatments for cannabinoid hyperemesis syndrome, highlighting haloperidol and capsaicin ointment as therapeutic options for this difficult-to-treat vomiting condition.
Review of 36 studies confirms cannabis impairs multiple driving functions and doubles or triples crash risk, with cannabis-alcohol combination increasing injury risk nearly 11-fold.
Six cannabis users hospitalized for hyperemesis had dangerously low phosphate levels that resolved spontaneously in hours, possibly from hyperventilation-driven redistribution.
Three new synthetic cannabinoids showed nanomolar potency and caused seizures, aggression, and neurotoxicity in mice, confirming their much greater danger compared to natural cannabis.
Low-dose pesticide exposure during rat development elevated endocannabinoid levels and decreased anxiety-like behavior, even at doses below traditional neurotoxicity thresholds.
Despite marijuana use doubling among Chilean teens from 2009-2013, rigorous analysis found the massive 2011 school protest movement had no causal effect on substance use.
Review of how GW Pharmaceuticals and the University of Mississippi produce consistent, medical-grade cannabis for clinical research, covering breeding, cultivation, and extraction.
Cannabis use disorder diagnoses in US hospitals nearly tripled from 2002-2011, with psychiatric disorders as the top comorbidity and patients trending older and sicker.
Pulmonology review showing marijuana smoke shares many harmful combustion products with tobacco smoke, affecting the respiratory tract of the estimated 2.5-5% of people who use cannabis globally.
Hemp seed extract improved memory and reduced brain aging markers in rats by boosting antioxidants, reducing inflammation, and decreasing Alzheimer's-related protein changes.
Novel peripherally restricted CB1 blocker TXX-522 produced weight loss and improved insulin sensitivity in obese mice without affecting food intake or entering the brain.
A potent CB1 blocker raised liver glucose production through sympathetic nerve activation, warning that strong CB1 inverse agonism in weight-loss drugs could worsen blood sugar control.
First reported case of cannabinoid poisoning from medically prescribed hemp seed oil in a preschool child, with neurological symptoms resolving after IV hydration.