Shared Genetic Factors Drive Much of the Overlap Between Alcohol, Tobacco, and Cannabis Dependence ↗
Twin study found over 60% of the shared vulnerability to alcohol, tobacco, and cannabis dependence was driven by common genetic factors.
Research library — page 13
Browse more cannabis research, findings, methods, and limitations.
Caffeine Made THC's Memory-Impairing Effects Worse, Not Better, in Rats ↗
In rats, caffeine did not offset THC's memory effects but actually worsened them, with a subthreshold THC dose impairing memory when combined with caffeine.
How the Endocannabinoid System Interacts With Alcohol Dependence ↗
Comprehensive review found the brain's endocannabinoid system plays a key role in alcohol's rewarding effects and is altered by chronic drinking.
Five Strategies for Making Cannabinoid Medicines More Effective With Fewer Side Effects ↗
Review identified five strategies for making cannabinoid medicines more effective while reducing psychoactive side effects, covering applications from pain to neurodegeneration.
Nabiximols (Sativex) for MS Spasticity, Pain, and Bladder Problems: What the Trials Show ↗
Review found nabiximols (THC/CBD spray) effectively treated spasticity, pain, and bladder dysfunction in MS, though long-term data were limited.
Cannabis May Both Relieve MS Symptoms and Protect Nerve Cells From Damage ↗
Review found cannabinoids may both relieve MS spasticity symptoms and protect nerve cells from disease-related damage.
The Endocannabinoid System Is Present in Embryos Before Brain Development Begins ↗
The endocannabinoid system is active in embryos before brain development begins, suggesting early pregnancy cannabis exposure could disrupt fundamental developmental processes.
Runner's High Has an Endocannabinoid Signature in Humans. Dogs Show It Too. ↗
High-intensity running raised blood endocannabinoids in humans and dogs, not in ferrets and not during walking.
CBD Reduced Lung Inflammation in Mice Through Adenosine Receptor Activation ↗
A single dose of CBD reduced lung inflammation across multiple markers in mice, working through the adenosine A2A receptor pathway.
CBD Reduces Nausea and Vomiting by Activating Serotonin Receptors in the Brain ↗
CBD suppressed vomiting and nausea-like behavior in animals by activating serotonin 5-HT1A receptors in a specific brainstem region.
Chronic Cannabis Users Show Brain Activation Changes in Social Thinking That Resemble Psychosis Risk Patterns ↗
Brain imaging found chronic cannabis users had altered activation in social cognition regions, matching patterns seen in psychosis-risk populations.
Depressive Symptoms Help Distinguish Cannabis-Induced Psychosis From Primary Psychotic Disorders ↗
Depression and insight measures distinguished cannabis-induced psychosis from primary psychotic disorders with 97% accuracy in hospitalized patients.
Cannabinoids Show Promise for Slowing Huntington's Disease Progression in Lab Studies ↗
Preclinical evidence showed cannabinoids, especially the THC/CBD combination in Sativex, had neuroprotective properties relevant to Huntington's disease.
Injecting Cannabinoids Directly Into Muscles Reduced Pain in Rats ↗
Cannabinoid agonists injected directly into muscles reduced pain in rats, with local administration outperforming systemic in one of two models tested.
Workplace Drug Testing in Italy Found Very Low Positive Rates, Possibly Due to Advance Notice ↗
Only 0.7% of Italian workers in safety-sensitive jobs tested positive for drugs, likely because the law requires them to be notified the day before testing.
Cannabis Boosted Creative Thinking in Less Creative People but Also Increased Psychosis-Like Symptoms ↗
Cannabis improved verbal fluency in people with low baseline creativity while increasing psychosis-like symptoms in all users.
Heroin Treatment Reduced Use of Most Drugs Over 18 Months, but Cannabis and Alcohol Use Stayed the Same ↗
Eighteen months of heroin treatment reduced heroin, cocaine, and benzodiazepine use, but cannabis and alcohol consumption remained unchanged.
Alcohol Withdrawal Disrupts the Endocannabinoid System in the Brain's Fear Center ↗
Alcohol withdrawal reduced endocannabinoid system gene expression in the rat amygdala, with repeated withdrawal cycles causing worse disruption.
The 98-Patient Case Series That Shaped Cannabinoid Hyperemesis ↗
Largest early CH series: frequent long-term use common, abdominal pain prevalent, 91 percent of those who tried hot bathing reported relief. Follow-up was scarce.
The Endocannabinoid System: A Master Regulator of Brain Health and Disease ↗
Overview described the endocannabinoid system as a master regulator involved in neuroprotection, pain, memory, neurogenesis, and immune function.
South Africans Viewed All Substance Users Negatively, but Saw Cannabis as Less Dangerous Than Alcohol ↗
South African survey found high stigma toward all substance users, but cannabis was rated less dangerous than alcohol, and men faced more coercive attitudes than women.
Fibromyalgia Patients Using Cannabis Had More Mental Health Problems and Drug-Seeking Behavior ↗
Among 457 fibromyalgia patients, 13% used cannabinoids, with herbal cannabis use linked to mental illness, opioid drug-seeking, and male sex.
Former Cannabis Users Recovered Learning Ability but Still Had Timing Problems in a Brain Task ↗
Former cannabis users recovered associative learning ability but still showed impaired response timing, suggesting lasting cerebellar changes after quitting.
Early Cannabis Use Was Linked to Nearly Triple the Risk of Suicide Attempt in French Students ↗
Early cannabis use was linked to a 2.9-fold increased risk of suicide attempt in French students, with different substance-suicide patterns across France and the US.
The "Gateway Drug" Sequence Did Not Predict Cannabis Use Disorder Better Than Peer Influence ↗
Longitudinal study found the order of trying drugs did not predict cannabis use disorder; peer influence was the key factor.
Adolescent THC Exposure Changed Gene Regulation in the Brain, Making Rats More Vulnerable to Heroin ↗
Adolescent THC exposure in rats altered gene regulation through epigenetic changes in the reward system, directly increasing vulnerability to heroin self-administration.
A THC/CBD Combination Protected Brain Cells in a Huntington's Disease Model ↗
A THC/CBD combination reduced brain cell death and inflammation in a rat Huntington's disease model, working through both CB1 and CB2 receptors.
What Works for Treating Substance Dependence: Medications Available for Some Drugs but Not Cannabis ↗
Review found effective medications for nicotine, alcohol, and opioid dependence, but none approved for cannabis or cocaine dependence.
Blocking Cannabinoid Receptors Improved Memory Problems During Morphine Withdrawal in Mice ↗
Blocking cannabinoid receptors improved memory deficits during morphine withdrawal in mice, with chronic treatment being more effective than a single dose.
THC Impaired Spatial Memory but Not Object Memory in Adolescent Monkeys ↗
THC selectively impaired spatial but not object working memory in adolescent monkeys, suggesting less mature brain functions are more vulnerable.
None of 10 Previously Reported Cannabis Genes Replicated in a Large Twin Study ↗
A study of 7,452 twins found none of 10 previously reported cannabis-associated genes replicated, suggesting earlier findings were likely false positives.
Oral Fluid Testing Detected All Drug Types Found in Blood Among Suspected Drug Drivers ↗
Oral fluid testing detected all drug types found in blood among 100 suspected drug drivers, offering a faster alternative to urine collection.
Genetic Influence on Substance Use Comorbidity Peaked in Adolescence and Declined Into Adulthood ↗
Twin study found shared genetic risk for nicotine, alcohol, and marijuana peaked at ages 14-17 and declined into adulthood as substance use became more environmentally driven.
Sativex Safety Review: Well-Tolerated With No Evidence of Dependence or Dose Escalation ↗
Safety review found Sativex was well-tolerated for MS spasticity with no evidence of dependence, dose escalation, or significant withdrawal upon stopping.
Cannabinoid Receptor-Expressing Neurons in the Brain's Reward Center Are Fast-Spiking Cells That Control Output ↗
CB1-expressing neurons in the brain's reward center are fast-spiking interneurons that become hyperexcitable during cocaine withdrawal, potentially suppressing reward circuit output.
Different Drug Tools Selectively Boost Either Anandamide or 2-AG in the Living Brain ↗
Research tools for boosting brain endocannabinoids work differently in rats versus mice, with FAAH and MAGL inhibitors selectively targeting anandamide or 2-AG respectively.
Blocking 2-AG Breakdown in the Spinal Cord Powerfully Reduced Pain Signaling in Rats ↗
Spinal administration of an enzyme inhibitor powerfully reduced pain signaling and blocked inflammation-induced sensitization in rats via endocannabinoid mechanisms.
Patients in Sativex Trials Did Not Become Unblinded, Confirming Reliable Results ↗
Analysis of 666 patients in three Sativex trials found no evidence of unblinding, confirming the validity of self-reported efficacy results.
Schizophrenia Patients Who Used Cannabis Actually Had Better Cognitive Function Than Non-Users ↗
Meta-analysis found schizophrenia patients who used cannabis had better cognitive performance than non-using patients, suggesting a different pathway to psychosis.
Cannabis Extract Nearly Doubled the Rate of Muscle Stiffness Relief in Multiple Sclerosis ↗
Phase III trial found oral cannabis extract nearly doubled muscle stiffness relief compared to placebo in 279 MS patients, with benefits for pain and sleep.
Systematic Review: What CBD Does (and Does Not) Do in Humans ↗
Systematic review of 34 human studies found preliminary CBD benefits for anxiety, insomnia, and epilepsy, with complex THC interactions depending on delivery route.
Medical Cannabis Patients Reported High Psychological Distress and Stress From Drug Law Enforcement ↗
Survey of 37 medical cannabis patients found elevated psychological distress and widespread exposure to drug law enforcement tactics.
Heavy Cannabis Users' Brains Lit Up in the Habit Region When Shown Positive Cannabis Associations ↗
Brain imaging showed heavy cannabis users activated habit-related brain regions for positive cannabis associations while non-users activated deliberate control regions.
Pregabalin and Topiramate Reduced Anxiety and Motor Symptoms During Cannabis Withdrawal in Mice ↗
Pregabalin and topiramate both reduced anxiety and motor symptoms during cannabinoid withdrawal in mice while reversing brain gene expression changes.
Cannabis Use Predicted Late College Dropout Even After Accounting for Depression ↗
Four-year study of 1,145 college students found cannabis use predicted late enrollment gaps while depression predicted early ones.
Students Using "Study Drugs" Actually Had Worse Grades Linked to Cannabis and Alcohol Problems ↗
Study of 984 college students found "study drug" use was linked to escalating cannabis and alcohol problems and declining academic performance, not academic ambition.
Only Half of Healthy Volunteers Experienced Psychotic Symptoms From THC, and Their Brains Responded Differently ↗
About half of healthy men experienced psychotic symptoms from THC while half did not, with distinctly different brain activation patterns between groups.
Veterans With Poor Sleep Quality Had Less Success Reducing Cannabis Use During Quit Attempts ↗
Veterans with poor perceived sleep quality reduced their cannabis use less during a 6-month quit attempt, even after accounting for PTSD and withdrawal.
Cannabis Impaired Driving-Related Brain Networks Even at Low THC Blood Levels ↗
Brain imaging showed cannabis disrupted attention and executive control networks while increasing self-focused brain activity, even at low blood THC levels.
First Combined Tobacco-Cannabis Quit Program Developed and Well-Received by Participants ↗
First group cessation program for simultaneous tobacco and cannabis quitting was developed through user research and received positive acceptability ratings.