Colorado emergency departments are seeing more cannabis-related illnesses since legalization ↗
Colorado EDs have seen rising cannabis-related presentations including psychosis, CHS, cardiac events, and pediatric exposures since legalization.
Research library — page 42
Browse more cannabis research, findings, methods, and limitations.
Your COMT gene variant determines how much THC impairs your working memory ↗
COMT Val/Val carriers were most vulnerable to THC-induced cognitive deficits. A COMT inhibitor reduced these effects, but THC's psychosis-like effects were independent of dopamine.
The endocannabinoid system controls fear and pain differently depending on which part of the prefrontal cortex is involved ↗
Endocannabinoid signaling in different prefrontal cortex subregions had opposing effects on pain suppression and fear behavior in rats.
Cannabis use changes DNA methylation in sperm, with potential multigenerational consequences ↗
Cannabis use alters DNA methylation in human sperm, potentially affecting offspring development and possibly future generations through epigenetic inheritance.
Medical marijuana programs in Canada, Germany, and Thailand show industry pressure outpacing evidence ↗
Analysis of medical marijuana programs in Canada, Germany, and Thailand shows industry pressure and self-medication driving adoption faster than evidence.
Cannabis use in psychosis patients is linked to antipsychotic treatment failure ↗
Cannabis use in psychosis patients was associated with antipsychotic treatment failure, including more medication switches and higher clozapine use.
Systematic review finds cannabis smoking linked to heart attacks and cardiovascular disease ↗
A systematic review of 85 studies found the majority linked cannabis smoking to increased risk of acute coronary syndrome and cardiovascular disease.
A cautionary review of health effects seen in Colorado after cannabis legalization ↗
Since legalization, Colorado has seen increases in psychosis, suicide, substance abuse, motor vehicle fatalities, pediatric exposures, and other harms.
A cannabinoid receptor gene variant predicts cognitive improvement in first-episode psychosis treatment ↗
A cannabinoid receptor gene variant (CNR1 rs7766029) predicted cognitive improvement over 18 months in first-episode psychosis patients.
Oral fluid THC testing predicts blood THC status, but accuracy drops at higher concentrations ↗
Oral fluid THC testing was good at detecting any blood THC, but less reliable at predicting specific blood concentrations relevant to impairment.
Drivers with children in the car were less likely to drink but just as likely to test positive for THC ↗
A Washington roadside survey found drivers with children were far less likely to drink but just as likely to test positive for THC.
Schizophrenia patients who used cannabis showed better brain processing than those who did not ↗
Schizophrenia patients who used cannabis showed better auditory processing (MMN) than non-using patients, possibly reflecting a less impaired subgroup.
Long-acting injectable antipsychotics reduced rehospitalization in cannabis-using psychosis patients ↗
Cannabis-using psychosis patients were more dissatisfied with medication and rehospitalized more, but long-acting injectable antipsychotics reduced this risk.
People with cannabis use disorder have an automatic attentional pull toward cannabis-related images ↗
Cannabis users showed involuntary attentional capture by cannabis cues within 125-200 ms, along with more errors and poorer selective attention.
Should medical cannabis use disqualify someone from receiving a kidney transplant? ↗
A 20-year-old was denied a kidney transplant listing due to medical cannabis use, highlighting ethical tensions as legal medical cannabis collides with transplant policy.
Medical cannabis significantly reduced pain scores in fibromyalgia patients over six months ↗
In 367 fibromyalgia patients, medical cannabis reduced median pain from 9 to 5 over six months, with 81% responding and mostly mild side effects.
A clinical review of CBD for epilepsy: effectiveness, drug interactions, and regulatory challenges ↗
CBD is FDA-approved for two childhood epilepsies but has significant drug interactions, liver risks with valproate, and regulatory challenges that affect patient access.
Long-term CBD for childhood epilepsy: 27% sustained response, but 81% had adverse events ↗
Over four years, CBD helped 27% of children with severe epilepsy (3 became seizure-free), but 81% had side effects and most discontinued.
CBD reduced brain inflammation and improved memory in diabetic rats with impaired brain blood flow ↗
CBD improved memory and reduced brain inflammation in diabetic middle-aged rats with impaired cerebral blood flow, through anti-inflammatory rather than neuroplasticity mechanisms.
THC plus stress during adolescence impaired fear extinction in adult mice ↗
Neither THC nor stress alone caused lasting anxiety-like brain changes, but the combination during adolescence impaired fear extinction in adult mice.
Ultra-Low THC Doses Protected Mouse Brains From Injury. Regular Doses Did the Opposite. ↗
Mouse studies showed THC at doses thousands of times below the psychoactive threshold protected against brain injury and cognitive decline, while standard doses impaired cognition.
Cannabinoids for rheumatic diseases: anti-inflammatory potential but lacking rigorous evidence ↗
Cannabinoids have theoretical benefits for rheumatic diseases, but reviews are outpacing actual trials and evidence remains insufficient.
About 1 in 4 multiple sclerosis patients at a Canadian clinic used cannabis products ↗
About 1 in 4 MS patients at a Canadian clinic used cannabis products, with oral and smoked/vaporized being the most common routes.
Non-psychoactive cannabinoids protected neurons in an Alzheimer's drug screening model ↗
Nine of 11 cannabinoids protected neurons in an Alzheimer's drug screening model, removed amyloid, and worked through both receptor-dependent and independent mechanisms.
Cannabis use frequency, cognitive self-perception, and anxiety are the strongest predictors of use disorder severity in young adults ↗
In young adult regular cannabis users, the strongest predictors of use disorder severity were use frequency, beliefs about cannabis impairing cognition, perceived cognitive deficits, and anxiety.
Your dispensary's strain names are genetically unreliable ↗
Genetic analysis found no basis for sativa/indica/hybrid labels and significant inconsistencies in the same strain from different dispensaries.
THC from vaping deposits on room surfaces, creating potential third-hand exposure ↗
THC was detected on room surfaces after cannabis vaping at levels up to 4,882 ng/m2, demonstrating third-hand cannabis exposure potential.
Patients who quit cannabis after first-episode psychosis had outcomes similar to never-users at 10 years ↗
At 10-year follow-up, first-episode psychosis patients who quit cannabis had outcomes matching never-users, while persistent users fared significantly worse.
Older cannabis users and medical users report fewer adverse effects and different withdrawal patterns ↗
Survey of 2,905 users found older adults and medical users experience fewer adverse effects, but medical users report more withdrawal symptoms. Only 17% thought cannabis is addictive.
Cannabis-related emergency department visits increased 7% annually from 2006 to 2014 ↗
US cannabis-related ED visits rose 7% annually from 2006-2014, with teenagers at highest risk and the West region growing fastest.
When choosing cannabis, consumers prioritize price, but medical users prioritize CBD content ↗
Consumer choice experiments showed medical cannabis users prioritize CBD content while recreational users and non-users prioritize price. Some warning messages paradoxically increased appeal.
The claim that medical cannabis laws reduce opioid deaths reversed when extended through 2017 ↗
The widely-cited finding that medical cannabis laws reduce opioid deaths reversed from -21% to +23% when extended through 2017, likely indicating a spurious correlation.
About 1 in 4 injured young drivers in Arizona tested positive for alcohol, THC, or both ↗
Among young injured drivers in Arizona, 30% tested positive for THC and 19% for alcohol, with substance users less likely to use safety equipment.
Cancer patients in Georgia struggle to access medical cannabis despite having legal authorization ↗
Cancer patients in Georgia with legal medical marijuana cards reported cannabis as helpful for pain but struggled with access (68%) and legality concerns (64%).
Brain imaging studies show altered cannabinoid signaling across multiple psychiatric disorders ↗
PET brain imaging found altered CB1 receptor binding across cannabis use disorder, alcohol use disorder, schizophrenia, PTSD, and eating disorders.
What we know about how cannabis legalization affects substance use: a policy review ↗
Medical cannabis laws increase adult but not adolescent use and may reduce opioid harms. Recreational law effects on youth are minimal so far, but long-term impacts remain unknown.
Canadian university students using cannabis medicinally do so mostly for mental health conditions with little evidence ↗
Among Canadian university students, 11% used cannabis medicinally (mostly for mental health), 38% replaced prescribed medications, and 14% met criteria for cannabis use disorder.
Low-dose CBD enhanced THC intoxication while high-dose CBD reduced it, especially in infrequent users ↗
A controlled trial found low-dose CBD enhanced THC intoxication while high-dose CBD reduced it, with the strongest effects in infrequent cannabis users.
Cannabis use history was associated with longer delays before psychosis treatment ↗
Cannabis use history predicted longer delays before treatment in first-episode psychosis patients, alongside age and negative symptoms.
In Rats, Low-Dose THC Felt Rewarding Through CB1 Receptors. Higher Doses Felt Aversive Through CB2. ↗
Rat study found THC enhances brain reward at low doses (CB1) but suppresses it at high doses (CB2) — a biological explanation for why more weed doesn't mean more fun.
Early CBD treatment prevented schizophrenia-like symptoms from developing in a rat model ↗
CBD given during adolescence prevented schizophrenia-like symptoms and normalized cannabinoid receptor changes in a rat model, while haloperidol did not.
How Colorado tried to protect youth in its legal cannabis market ↗
Five years into legal cannabis, Colorado stakeholders identified gaps between youth protection goals and real-world enforcement.
Testing an Alzheimer's drug to counteract cognitive effects of cannabis use ↗
Pilot trial found galantamine was safe in cannabis use disorder but showed no cognitive benefits beyond placebo over 10 days.
Long-term cannabis use patterns in Canadian youth linked to risky driving ↗
Ten-year Canadian study found chronic and increasing cannabis users were most likely to drive impaired as young adults.
What the evidence says about cannabis for inflammatory bowel disease ↗
Cannabis may improve IBD symptoms and quality of life, but no evidence yet shows it reduces underlying inflammation or heals the gut.
12-year-old with severe Tourette syndrome treated with vaporized cannabis ↗
A 12-year-old boy with severe Tourette syndrome experienced near-complete tic remission with vaporized cannabis and oral THC, with no adverse effects reported.
Heavy marijuana smoking linked to COPD and faster lung decline in older adults ↗
Study of 1,285 adults aged 40+ found heavy marijuana smoking more than doubled COPD risk and accelerated lung decline beyond tobacco alone.
What inhaled cannabis smoke does to the lungs ↗
Review finds cannabis smokers show similar airway symptoms as tobacco smokers, plus unique immune cell deficits, but COPD progression from cannabis alone remains unclear.
Most Tourette patients report benefit from medical cannabis in real-world use ↗
Survey of 42 Tourette patients found most reported benefit from medical cannabis, rating efficacy 3.85 out of 5, though 10 eventually stopped treatment.
Synthetic cannabinoid JWH-018 impairs cognition and triggers dissociation in some users ↗
Controlled study found the synthetic cannabinoid JWH-018 impaired memory and tracking in all users, with dissociation and amnesia in those who got the strongest high.