Browse more cannabis research, findings, methods, and limitations.
A daily diary study of 97 young adults found that cannabis-related enhancement and social motives were the primary drivers of same-day alcohol and cannabis co-use, more so than alcohol-related motives.
The pancreas has its own endocannabinoid system that helps regulate insulin secretion. Preclinical research suggests CB1 receptor blockers could protect beta cells from obesity-related inflammation and damage.
Young adult cannabis users fall into three pain groups: low pain (56%), multiple pain conditions (27%), and nonspecific pain (16%). Those with more pain were more likely to use cannabis medically and consume edibles.
A review found gestational cannabis exposure is associated with impaired placental blood flow, smaller birth size, and potential neurodevelopmental and metabolic risks in children, though definitive evidence remains limited.
Delta-8 THC is chemically similar to standard THC but sold unregulated in gas stations and online. The lack of safety standards has led to poisoning reports, including pediatric emergencies with children arriving unconscious.
Preclinical research suggests that blocking endocannabinoid-degrading enzymes (MAGL and FAAH) could protect brain cells from Alzheimer's-related damage, reduce inflammation, and potentially improve cognitive function.
CBD interacts with a wide range of medications including anti-epileptics, antidepressants, opioids, and even common drugs like acetaminophen. The interactions occur primarily through effects on liver enzymes that metabolize other drugs.
A Nature Reviews Neuroscience paper found cannabis exposure during pregnancy and adolescence impairs brain development through epigenetic changes that persist into adulthood and can be passed to future generations.
A review of 10 clinical studies found CBD may reduce psychotic symptoms caused by THC and positive symptoms of schizophrenia, though results for treating cannabis use disorder were mixed.
A children's hospital study found that delayed recognition of cannabis exposure in kids led to twice as many diagnostic tests, four times the avoidable costs, and hospital stays averaging 18 hours versus 4 hours for adolescents.
A large genetic study found no causal relationship between cannabis use and type 2 diabetes risk. The analysis used genetic data from nearly one million people to separate causation from correlation.
A study of 921 driver fatalities in Ontario found more tested positive for THC (251) than alcohol (241). THC-positive crashes were spread throughout the week and more often involved multiple vehicles.
Only nabiximols is approved and safety-monitored for neuropathic pain. The many other cannabis products widely used for nerve pain lack adequate safety data, making it impossible to establish correct risk-benefit profiles.
Cannabinoids alter immune function by changing which microRNAs immune cells produce. These tiny RNA molecules regulate gene expression, providing a molecular mechanism for the anti-inflammatory effects observed with cannabinoid use.
A Turkish clinic treated 33 autistic children with low-dose CBD-enriched cannabis for a median of 6.5 months. About a third showed improved behavior, and nearly a quarter improved in language, with no significant side effects.
CBD's proven success treating severe epilepsy has opened the door to investigating its potential for depression, anxiety, PTSD, addiction, and autism. Preclinical and early clinical data show promise across multiple neuropsychiatric conditions.
A study of 152 youths found that more severe cannabis use disorder was linked to poorer recognition of sad and fearful facial expressions, independent of conduct disorder. This could represent a pathway through which cannabis increases aggression risk.
In a controlled THC study of 36 men, both a genetic variant (AKT1 rs1130233) and DNA methylation independently influenced how THC affected fear-related brain activity, with the epigenetic state partially mediating the genetic effect.
An fMRI study found adolescent-onset cannabis users learned new words significantly slower than non-users. Brain imaging revealed disrupted activation in the parahippocampal gyrus, midbrain, and thalamus during learning.
A pilot trial of 16 adults with treatment-resistant Tourette's found a THC/PEA combination reduced tics by over 20% within one week. Twelve of 16 participants chose to continue treatment in the extension phase.
Cannabis vaping doubled among U.S. adults from 2017 to 2019, tripling among 18-24 year olds. While not linked to respiratory symptoms, cannabis vaping was strongly associated with heavy drinking and other high-risk behaviors.
Among 878 fibromyalgia patients using CBD, 72% reported substituting it for other medications. Over half substituted for opioids, and most said they reduced or stopped those medications entirely.
A COVID-19 survey of 353 medical cannabis users found over half increased use of alcohol, sleep aids, or other substances. About 40% attributed this to changed cannabis access during the pandemic.
A survey of 2,701 fibromyalgia patients found about a third currently use CBD, mainly for pain. Most reported improvement, but two-thirds who told their doctor did not ask for physician guidance on CBD use.
A review found cannabis does not appear to treat the underlying inflammation in IBD but consistently reduces abdominal pain in both animal and human studies, offering potential symptom relief alongside standard therapy.
The first placebo-controlled trial of smoked cannabis for PTSD in 80 veterans found all groups improved, but no cannabis preparation outperformed placebo over three weeks. The strong placebo response complicates interpretation.
Most state cannabis regulatory systems ignore behavioral science evidence. This review argues that applying psychology to understanding consumers, industry tactics, and regulatory design could substantially reduce cannabis-related public health harms.
A Cochrane review of four trials (126 participants) found very low to low certainty evidence that cannabinoids have little or no meaningful effect on cognition or behavioral symptoms in dementia. The evidence base is too small for conclusions.
Adverse event reports from recreational cannabis in France tripled between 2012 and 2017, reaching 2,217 cases. Psychiatric effects were most common (51%), and cannabinoid hyperemesis syndrome emerged as a new concern from 2015.
Cannabinoid receptors (CB1 and CB2) are found on nearly all immune cell types within tumors. Activating these receptors can modulate cancer-related immune responses, opening potential therapeutic avenues.
Despite growing legalization, key questions about cannabis and driving remain unanswered, including the dose-response relationship, tolerance effects, edible impairment timelines, and differences between medical and recreational users.
An NCI workshop found strong evidence for cannabinoids treating chemo nausea and some evidence for cancer pain, but highlighted underappreciated risks including infections, drug interactions, and the challenge of Schedule I research barriers.
Cannabis has established medical uses for pain, nausea, spasticity, and epilepsy. However, high-THC exposure causes adverse effects across nearly every body system, with children at particular risk for serious neurological toxicity.
A simulator study of 85 adults found occasional cannabis users showed significant driving impairment after smoking, while daily users showed a non-significant trend. Daily users had 5-6 times higher blood THC but drove slower as a compensatory behavior.
A medical cannabis patient experienced a dangerous spike in warfarin blood-thinning levels (INR 5.2) after increasing his THC dose by just 7.35 mg, likely because both drugs compete for the same liver enzymes.
In a study of nearly 3,000 people with psychotic disorders, cannabis users had lower quality of life and worse functioning. Neither starting nor stopping cannabis changed outcomes within one year, suggesting accumulated effects from years of use.
Among 446 methadone patients, frequent cannabis users were 71% less likely to report a nonfatal opioid overdose in the past year (3% vs 9%), though the cross-sectional design prevents causal conclusions.
A practical clinician guide finds cannabis may help some IBD symptoms but does not reduce inflammation. Clinicians should discuss dosing inconsistencies, dependence, and cannabinoid hyperemesis syndrome with IBD patients who use cannabis.
Synthetic cannabinoids (Spice, K2) are far more potent than natural cannabis, with 207 compounds identified in Europe. As full receptor agonists, they cause severe toxicity including renal damage, respiratory depression, and death.
Cannabis and THC show no benefits for athletic performance and may impair cardiovascular function during exercise. CBD shows more promise for recovery, potentially aiding sleep, pain management, and mild traumatic brain injury recovery.
Almost all cannabis driving research uses ~6% THC products, while consumers buy flower at 20%+ THC and concentrates above 60%. This gap means the true impact of modern cannabis on driving may be significantly underestimated.
In a small simulator study, cannabis users who felt stimulated showed less driving impairment than those who felt stoned. Subjective experience predicted steering behavior, while actual lane control was predicted by cannabis dose.
A BMJ clinical guideline weakly recommends trying non-inhaled medical cannabis for chronic pain when standard treatments fail. The recommendation balances small improvements in pain, function, and sleep against mostly minor, temporary side effects.
A study of 2,577 mother-child pairs found prenatal cannabis exposure (with tobacco) was linked to higher stress hormone levels in children at age 6, suggesting lasting effects on the developing stress response system.
Analysis of over 239,000 traffic-injury emergency visits in Ontario and Alberta found no increase in driver injuries after Canada legalized cannabis in October 2018, including no increase among youth drivers.
A daily cannabis user with no symptoms of gastroparesis had 500 mL of stomach contents during surgery despite proper fasting, raising concerns about hidden aspiration risks in cannabis users undergoing anesthesia.
One in ten licensed Ontario high school students reported driving within an hour of using cannabis. Cannabis dependence was the strongest predictor (OR 12.7), followed by low perceived risk and pro-legalization attitudes.
A systematic review found only five studies on cannabis and head and neck cancer, none with standardized dosing. No conclusions about benefits or harms could be drawn from this extremely limited evidence base.
Eight infants with treatment-resistant West syndrome received CBD-enriched cannabis oil. Four achieved more than 50% seizure reduction, with EEG improvements in seven of eight. Side effects were mild and temporary.
A survey of 281 MS patients in Argentina found over a third use cannabis, but most never discussed it with their neurologist. Chronic pain and younger age were the strongest predictors of use.