Browse more cannabis research, findings, methods, and limitations.
Survey of 1,651 Canadian workers found 25% of cannabis users had used at or before work. Workplace users were more likely to use daily, use high-THC, and use for medical reasons.
Among 113 women with chronic pelvic pain, 23% used cannabis as an adjunct therapy. Nearly all users (96%) reported symptom improvement, and over a third reduced their healthcare visits as a result.
A systematic review of 11 studies found no clear evidence that cannabis compounds cognitive deficits in youth with ADHD, though neuroimaging showed brain differences. The evidence is limited and potentially underpowered.
Among 387 people who inject drugs, cannabis was commonly used for pain relief, emotional support, and as an opioid substitute. Using cannabis for pain was strongly linked to using it as an opioid replacement.
Rural Australian healthcare providers were generally positive about medical cannabis for older patients but identified stigma, complex regulations, limited rural access, and restrictive driving laws as major barriers to prescribing.
A systematic review of five trials found the synthetic cannabinoid nabilone may reduce agitation in dementia, but natural THC showed no benefit. No studies have tested cannabinoids for cognitive decline in dementia.
A systematic review of 18 publications found cannabis before exercise reduces endurance, increases heart rate and oxygen demand, and impairs balance. Cannabis is ergolytic (performance-reducing), not performance-enhancing.
Blocking the enzyme FAAH in immune cells from Alzheimer's patients reduced inflammation and shifted cells toward a protective state, suggesting endocannabinoid system modulation could offer a new therapeutic approach.
Women over 50 comprised 57% of cannabis poison control cases and were nearly twice as likely as men to call about therapeutic errors rather than misuse, often involving edibles and other non-plant cannabis products.
Cannabis poison control cases among adults over 50 increased 18-fold from 2009 to 2019, with non-plant products surging 51-fold. Synthetic cannabinoid products carried twice the risk of serious medical outcomes.
Synthetic cannabinoids (Spice, K2) are full receptor agonists, unlike natural THC, explaining their extreme potency. They cause severe toxicity including heart damage, immune suppression, and death.
A Canadian survey of 5,630 emerging adults found both habitual and casual cannabis users had about 1.8 times the odds of traffic violations, with the association strongest among younger users and those not using other drugs.
A study of 703 adolescents found cannabis use linked to specific DNA methylation changes in immune cells. Notably, patterns in T cells and monocytes overlapped with brain tissue findings from psychosis research.
A perspective piece warns that many reported CBD lab activities may be false positives caused by the substance forming tiny particles in solution, rather than genuine drug interactions. This could reshape cannabinoid research.
A third of young cannabis-using Ontario drivers reported driving high, with 42% planning to do so again. Past behavior, low moral awareness, and low perceived danger were the strongest predictors of future cannabis-impaired driving.
In 124 patients with schizophrenia in a high-security hospital, cannabis use disorder was not linked to violence or impulsivity. Alcohol use disorder was nearly four times more likely to be associated with violent behavior.
In 15 young patients with cannabinoid hyperemesis syndrome, 14 had urinary THC metabolite levels above 100 ng/mL. This threshold could help doctors diagnose CHS faster and avoid unnecessary testing.
Cannabis only increased psychosis risk in people with pre-existing elevated inflammation, providing the first human evidence for a two-hit hypothesis. Cannabis did not cause the inflammation itself.
Survey of 1,485 medical cannabis patients in Michigan found that the 72 with cancer used less cannabis, less often, and were less likely to smoke it than non-cancer patients.
Tracking 552 young cannabis users from age 19 to 22, psychotic-like experiences did not predict changes in cannabis use, but later age of first use predicted steeper increases.
THC caused dose-dependent repetitive behavior in zebrafish that was reduced by an antipsychotic and a CB2 receptor blocker but not a CB1 blocker, offering a new model for studying cannabis-psychosis links.
Retrospective study of 423 IBD patients found that preadmission cannabis use was associated with higher inpatient opioid doses, even after adjusting for disease severity and prior opioid use.
Analysis of 3,785 Australian twins found five drug use patterns, with persistent polydrug use showing 94% heritability and links to conduct and antisocial personality disorders.
Review of preclinical evidence suggests CBD may help clear toxic protein aggregates in neurodegenerative diseases by modulating the proteostasis network, though human data remains limited.
Analysis of 110M transactions in Washington's legal market showed extracts growing to 28.5% of sales, with falling THC prices and dabs dominating the concentrate category.
Study of 307 healthy adults found no link between cannabis use and Kamin blocking (an associative learning task impaired in schizophrenia), though current users reported more schizotypy and aberrant salience.
L-theanine pretreatment in adolescent rats prevented the long-term dopamine dysregulation, molecular changes, and behavioral abnormalities caused by THC exposure.
Meta-analysis of 10 MRI studies found schizophrenia patients with and without cannabis use showed overlapping brain volume reductions, with no significant differences between groups.
Michigan saw 426 pediatric cannabis exposures from 2008-2019, doubling every 2.1 years after medical legalization, with young children mostly ingesting products and teens mostly inhaling.
Systematic review of 38 longitudinal studies found that brain development delays, especially in executive functioning, both precede and result from adolescent substance use, with harm tied to frequency and recovery tied to duration.
Survey of 200 osteoarthritis patients found 24% had tried CBD products, but CBD users reported significantly worse pain scores than non-users at their initial orthopedic evaluation.
Rats exposed to THC around birth showed lasting epigenetic changes in dopamine receptor genes and schizophrenia-like behaviors, but adolescent CBD treatment reversed the damage. Similar epigenetic changes were found in human schizophrenia patients.
Analysis of US poison control data from 2017-2019 found rising cannabis exposure reports, with manufactured products and plant materials showing different patient demographics and clinical patterns.
Case series of six children in Italian palliative care found medical cannabis reduced seizure frequency and pain over one year with only mild, transient side effects.
Two studies with 808 and 391 adolescents found that tailored gain-framed messages reduced cannabis use intentions in at-risk teens, especially after first destabilizing their resistance to prevention messaging.
Comprehensive screen of 12 cannabinoids against 6 liver enzymes found CBD and THC were the strongest inhibitors, with minor cannabinoids in full-spectrum products adding additional risk.
Analysis of ED data from 29 states found recreational cannabis laws reduced opioid-related emergency visits by 7.6% for two quarters, with effects concentrated in men aged 25-44, but the reduction faded after six months.
Scoping review of seven controlled trials found medical cannabis patients showed THC dose-dependent cognitive decline that fully resolved within 4 hours in every study.
Analysis of 461,706 Florida students found blunt use declined from 2010-2015 then reversed sharply, with notable increases among girls, middle schoolers, and white students through 2020.
URB597, which boosts natural endocannabinoids, prevented anxiety and depression in mice during methamphetamine withdrawal through CB1, CB2, and TRPV1 receptor pathways.
Gabapentin reduced physical withdrawal signs (tremors, head twitches) and restored motivation in THC-withdrawn mice, but did not affect stress hormones or all behavioral measures.
Pilot RCT of CBD in eight children with intellectual disability found 100% adherence, no serious side effects, and a preliminary signal of benefit for severe behavioral problems.
Study of 2,051 European teens found endocannabinoid gene interactions (CNR1, MGLL, DAGLA) associated with alcohol use disorder risk, with partial replication in 772 Canadian adolescents.
Blocking CB2 receptors during adolescence in rats impaired Pavlovian reward learning in adulthood but left instrumental conditioning intact, revealing a selective role for CB2 in reward system development.
Third potency monitoring report: THC continued rising through 2019, but the THC:CBD ratio suddenly reversed as CBD products entered the market post-2018 Farm Bill.
Systematic review of 12 economic evaluations found medicinal cannabis may be cost-effective for MS spasticity and Dravet syndrome, but results varied widely by product, indication, and setting.
The first 129 patients in the UK Medical Cannabis Registry showed significant improvements in anxiety, sleep, pain, and quality of life at 1 and 3 months, with 24% reporting adverse events.
Review showing 2-AG endocannabinoids gate dopamine value signals across reward, timing, and threat avoidance — explaining why cannabis broadly affects motivation.
Validated mouse model showed cannabis smoke increased lung macrophages without neutrophil infiltration, plus elevated immune mediators, in both male and female mice.
In 2018, synthetic cannabinoids contaminated with rat poison anticoagulants caused 174 hospitalizations and 5 deaths in Illinois, the first mass poisoning event of its kind.