Teenagers who smoke blunts often pick up cigarillo smoking as a separate tobacco habit ↗
Interviews with 30 teens found marijuana blunt use frequently led to standalone cigarillo tobacco smoking, with group sharing and substitution driving co-use.
Research library — page 32
Browse more cannabis research, findings, methods, and limitations.
A culturally tailored HIV prevention program also reduced marijuana use among American Indian middle schoolers ↗
A culturally tailored HIV prevention program reduced marijuana initiation risk by 17.3% among American Indian middle schoolers, though it did not reduce use frequency among initiators.
A new oral CBD capsule delivered more CBD into the bloodstream than the Sativex mouth spray ↗
New oral CBD formulation (PTL101) delivered 34% more CBD into the bloodstream than Sativex spray, with safe and efficient delivery in healthy volunteers.
Dronabinol (synthetic THC) is approved for appetite loss in AIDS and shows promise in cancer ↗
Review of dronabinol (synthetic THC) for appetite loss: FDA-approved for HIV/AIDS since 1985, new oral solution since 2016, but no cancer indication despite clinical need.
Cannabis use did not worsen opioid treatment outcomes in patients on buprenorphine ↗
Among 100 men on long-term buprenorphine, cannabis users (35%) had comparable opioid outcomes, employment, and quality of life to non-users, despite lower buprenorphine doses.
Non-medical marijuana use was linked to worse depression and higher suicidal thoughts over time ↗
Over 12 months, depressed outpatients who used marijuana non-medically showed less improvement in depression and suicidal ideation and attended fewer psychiatry visits.
Cannabis-using psychosis patients initially received less severe diagnoses but caught up at second hospitalization ↗
Cannabis-using psychosis patients were initially diagnosed with severe mental illness at lower rates (20% vs 53%), but both groups reached 80% severe diagnoses by second hospitalization.
A CB1 receptor blocker that avoided psychiatric side effects reduced binge drinking in mice ↗
A novel CB1 neutral antagonist reduced binge alcohol drinking and dopamine reward signaling in mice without the psychiatric side effects of previous CB1 blockers.
Most migraine patients using medical cannabis chose high-THC hybrid strains and many replaced opioids ↗
Survey of 2,032 medical cannabis patients found 88% of headache patients had probable migraine, preferred high-THC hybrids, and 41-60% replaced prescriptions, most often opioids.
A comprehensive guide to the medicinal properties of cannabinoids, terpenes, and flavonoids in cannabis ↗
Comprehensive review catalogues medicinal properties of individual cannabinoids, terpenes, and flavonoids, explaining the entourage effect and building the case for strain-specific cannabis medicine.
Genetic variations in dopamine genes interacted with early cannabis use to alter hippocampal brain structure ↗
Brain imaging of 59 young men found early cannabis use altered hippocampal subregion volumes, with effects modified by the DAT1 dopamine transporter gene variant.
Only five risk factors for schizophrenia held up under rigorous review, and cannabis was one of them ↗
Umbrella review of 98 associations found only five truly robust risk factors for schizophrenia: childhood adversity, cannabis use, obstetric complications, adult stress, and low folate.
A surveillance tool tracked marijuana retail marketing practices and regulatory compliance in Seattle ↗
A validated surveillance tool found most Seattle marijuana retailers complied with age rules but engaged in promotional marketing, with only 1 of 25 displaying health warnings.
Not all high-CBD cannabis extracts work the same, despite having identical CBD levels ↗
Profiling 94 phytocannabinoids across 36 strains showed that high-CBD extracts with equal CBD content produced different anticonvulsant effects, proving THC/CBD ratios alone are insufficient.
People who get psychotic symptoms from THC already have different hippocampal brain activity at baseline ↗
People who got psychotic symptoms from THC already had higher hippocampal brain activity during learning under placebo, suggesting a pre-existing neural marker of vulnerability.
CBD oral solution was FDA-approved for severe childhood epilepsies alongside other emerging antiepileptic drugs ↗
Conference report documents FDA approval of CBD oral solution for Lennox-Gastaut and Dravet syndromes, the first cannabis-derived FDA-approved medication.
The endocannabinoid system shows promise for bladder pain but faces challenges in clinical translation ↗
Review finds strong preclinical evidence for endocannabinoid-based bladder pain treatment but identifies pharmacological challenges including TRPV1 activation and complex enzyme interactions.
Whole-plant cannabis extract was more effective against breast cancer cells than pure THC alone ↗
Whole-plant cannabis extract outperformed pure THC against three breast cancer subtypes in lab and animal models, with different mechanisms suggesting a genuine entourage effect.
Brain scans reveal different patterns of altered function in adult versus adolescent cannabis users ↗
Meta-analysis of 20 fMRI studies found cannabis users show altered brain activation patterns, with different changes in adults (temporal/frontal regions) versus adolescents (parietal/putamen).
Young psychosis patients who use cannabis have worse cognitive function than non-using patients ↗
Meta-analysis of 14 studies found young psychosis patients who currently use cannabis perform worse on IQ, verbal learning, and working memory, except for set-shifting where they excelled.
Both maternal and paternal cannabis use during pregnancy were linked to psychotic-like experiences in children at age 10 ↗
Both maternal (38% increase) and paternal (44% increase) cannabis use during pregnancy predicted offspring psychotic-like experiences at age 10, suggesting shared genetics rather than direct prenatal exposure.
Two competing paths for cannabis medicine: whole-plant extracts versus single-molecule drugs ↗
Commentary examines two cannabinoid drug development paths: whole-plant extracts offering entourage effects versus single-molecule drugs offering precision, with legalization complicating both.
Only 7 randomized trials have tested smoked cannabis, and the evidence for most conditions was limited ↗
Review of only 7 randomized trials of smoked cannabis found no pain benefit, impractically brief glaucoma relief, but consistent appetite stimulation.
Medical cannabis in Europe is mostly limited to the spray Sativex, with little whole-plant use ↗
Survey of 17 European countries found medical cannabis mostly limited to Sativex spray, with little whole-plant use and no personal growing allowed, contrasting sharply with the US.
People with ADHD were three times more likely to use cannabis, and hyperactive types started youngest ↗
Adults with ADHD used cannabis at 3x the rate of those without, with the hyperactive subtype starting at age 13.8 versus 16.3 for inattentive, and 4x higher personality disorder rates.
Substance use including cannabis was consistently linked to suicidal thoughts and behavior across developing countries ↗
Systematic review of 108 studies found consistent links between substance use (including cannabis) and suicidal ideation and behavior across low- and middle-income countries.
Nearly half of young multiple sclerosis patients used marijuana, most for symptom relief despite recognizing memory effects ↗
Survey of 52 young MS patients found 48% used marijuana for relaxation and symptoms, with 64% of users acknowledging negative memory and focus effects.
The CB1 cannabinoid receptor plays a role in how the tongue detects dietary fat ↗
Mice lacking CB1 cannabinoid receptors showed reduced fat taste preference, with impaired calcium signaling in taste bud cells and lower GLP-1 hormone levels.
CBD shows promise for severe epilepsy but faces challenges with drug interactions and inconsistent absorption ↗
Review confirms CBD efficacy for Dravet and Lennox-Gastaut syndromes but highlights practical challenges including drug interactions, variable absorption, and unclear mechanisms.
Cannabis and CBD product exposure in dogs and cats is rising as legalization expands ↗
Veterinary review documents rising pet exposures to marijuana, CBD, and synthetic cannabinoids, with dogs especially sensitive to THC due to higher cerebellar CB1 receptor density.
Cannabis and the endocannabinoid system may play roles in several ear, nose, and throat conditions ↗
Review finds the endocannabinoid system is involved in several ENT conditions, with therapeutic potential for pain, inflammation, and head/neck cancers alongside known risks from cannabis smoking.
THC impairs short-term memory through a specific protein signaling pathway in the hippocampus ↗
THC impairs short-term memory through hippocampal PKC signaling and long-term memory through a separate mTOR pathway, with PKC blockers fully preventing the short-term memory deficit.
Low-Dose THC Improved Memory in Aging Mice. Higher Doses Impaired It in Young Ones. ↗
THC impairs cognition in young brains but animal research shows very low doses may restore memory and protect against neurodegeneration in aging brains — a biphasic dose-response.
A 4-year study found no evidence that cannabis improved pain or reduced opioid use in chronic pain patients ↗
Four-year study of 1,514 chronic pain patients on opioids found cannabis users had worse pain, more anxiety, and lower self-efficacy, with no evidence of opioid reduction.
Cannabis was the third most common substance in emergency department visits, with sex differences in patterns ↗
Analysis of 10,511 substance-related ED visits found cannabis third most common (14.4%) after alcohol and opioids, with sex-specific age differences in presentation patterns.
Chronic CBD exposure reduced testosterone and sperm quality in young male mice ↗
Male mice given daily CBD for 34 days showed 76% testosterone reduction, 38% fewer sperm, and sperm abnormalities persisting after a 35-day recovery period.
College students who vaped cannabis were influenced by peers who also started vaping, not just peers who used any cannabis ↗
Among 1,313 college freshmen, 5.9% started vaping cannabis during their first year, driven specifically by peers who also started vaping cannabis rather than general cannabis or e-cigarette users.
Sativex spray for MS spasticity did not impair driving and most patients reported driving improvement ↗
Review found no increase in accidents from Sativex spray in MS patients, with most reporting improved driving after treatment, though blood THC may exceed legal limits in some countries.
An online school program reduced teenagers' intentions to use synthetic cannabis for up to 2 years ↗
Online school program reduced teenagers' intentions to use synthetic cannabis by 2 years, with controls 3.5x more likely to intend use, but only when all 4 lessons were completed.
Cannabis withdrawal symptoms in adults with ADHD looked similar to those in people without ADHD ↗
Among 23 cannabis-dependent adults with ADHD, 96% had withdrawal symptoms similar to non-ADHD populations, with money being the top motivation (87%) to quit.
Three patients with a rare blistering skin disease reported faster healing and less pain using topical CBD oil ↗
Three patients with the rare blistering condition epidermolysis bullosa reported faster wound healing, less blistering, and pain relief from topical CBD, with one stopping opioids completely.
A schizophrenia risk gene did not alter the developmental trajectory of the brain's endocannabinoid system in mice ↗
Mice with a schizophrenia risk gene showed normal endocannabinoid system development across 8 time points, suggesting their heightened cannabis sensitivity operates through other mechanisms.
The endocannabinoid system in MS could address both symptoms and disease progression ↗
Comprehensive review finds clinical evidence for cannabinoids managing MS symptoms (spasticity, pain) and preclinical evidence for neuroprotective effects that could slow disease progression.
Nearly 73% of marijuana users continued using over a year, with early initiation and weekly use predicting persistence ↗
National study tracked marijuana transitions: 2.4% of never-users initiated, 10.4% of former users returned, and 72.5% continued over one year, with early initiation and frequent use predicting persistence.
Synthetic cannabinoids are more potent and far more dangerous than natural cannabis ↗
Review finds synthetic cannabinoids bind brain receptors with much higher potency than natural cannabis, causing psychosis, kidney failure, cardiac problems, and death.
Cannabis-using psychosis patients had more hospital readmissions and longer stays over 6 years ↗
Six-year follow-up of 161 early psychosis patients found cannabis use predicted more hospital readmissions and longer stays, especially in male and Black patients.
People who had used cannabis before were less affected by THC than those who had never tried it ↗
THC challenge study found never-users experienced more psychotic symptoms and brain disruption than modest prior users, suggesting even limited cannabis exposure creates tolerance-like neuroadaptation.
Even modest previous cannabis use blunted THC's effects on psychosis symptoms and brain function ↗
THC challenge study found modest prior cannabis users had worse baseline cognition but were protected from THC's psychotic effects, showing tolerance from even limited exposure.
Medical marijuana dispensary customers did not match the demographics of their surrounding neighborhoods ↗
Survey of 132 patients at 4 dispensaries found customer demographics differed significantly by location and did not match surrounding neighborhoods, suggesting market segmentation.
Your genes may determine how much cannabis affects your thinking and memory ↗
Review of 13 studies found that COMT and other dopamine-related gene variants modulate how cannabis impairs working memory, attention, and other cognitive functions.