Pregnant individuals described how the COVID-19 pandemic changed their cannabis use ↗
Qualitative study found COVID-19 pandemic increased stress and isolation that drove changes in prenatal cannabis use among pregnant individuals.
Research library — page 81
Browse more cannabis research, findings, methods, and limitations.
Prenatal cannabis use was associated with higher SARS-CoV-2 infection risk in California pregnancies ↗
Large California study of 58,114 pregnancies found prenatal cannabis use associated with higher SARS-CoV-2 infection risk after controlling for confounders.
Cannabis extracts reduced inflammatory signaling in human immune cells in the lab ↗
Lab study found cannabis extracts reduced inflammatory cytokine release in human macrophages, supporting anti-inflammatory potential at the cellular level.
Clinical trial tested how CBD changes THC effects when taken together orally ↗
Randomized trial found CBD dose-dependently altered THC blood levels and effects when co-administered orally in healthy adults.
Young adults who had pediatric bariatric surgery showed notable marijuana and e-cigarette use ↗
Longitudinal study found marijuana and e-cigarette use among young adults who had pediatric bariatric surgery, raising post-surgical substance use concerns.
Review covers how plant and body-made cannabinoids affect brain diseases ↗
Review examines how plant and endogenous cannabinoids affect CNS diseases, finding diverse pharmacological activities with varying levels of clinical evidence.
CBD did not significantly improve gastroparesis symptoms over placebo in a controlled trial ↗
Randomized trial found 4 weeks of pharmaceutical CBD did not significantly improve symptoms in idiopathic or diabetic gastroparesis versus placebo.
Heavy cannabis use led to bullous lung disease and a collapsed lung in a young man ↗
Case report documents spontaneous pneumothorax from cannabis-induced bullous lung disease in a young adult, highlighting an underrecognized smoking complication.
Randomized trial tested THC, CBD, and their combination for peripheral neuropathic pain ↗
Four-arm randomized trial compared CBD, THC, CBD/THC combination, and placebo capsules for peripheral neuropathic pain.
Prenatal cannabinoid exposure altered reproductive cell development differently in male and female offspring ↗
Animal study found prenatal cannabinoid receptor activation caused sex-specific epigenetic changes in offspring germ cells via histone modifications.
Many older California adults hesitated to tell their doctors about medical cannabis use ↗
Mixed-methods study found many older California adults hesitated to disclose medical cannabis use to doctors due to stigma and fear of judgment.
An 18-year-old with CHS developed dangerous phosphorus depletion from severe vomiting ↗
Case report of severe hypophosphatemia in an 18-year-old CHS patient highlights an underrecognized electrolyte complication of cannabinoid hyperemesis syndrome.
Review of 10 clinical trials supports CBD effectiveness for Dravet syndrome in children ↗
Review of 10 clinical trials confirms CBD reduces seizures in pediatric Dravet syndrome with manageable side effects and notable clobazam interactions.
Chicago parents had gaps in cannabis law knowledge and health effects, and rarely discussed it with teens ↗
Chicago parent survey found knowledge gaps about cannabis laws and health effects, with many parents not discussing cannabis with their adolescents.
Mental health problems and substance use often co-occurred in Canadian adults during COVID-19 ↗
Survey of 14,897 Canadian adults found concurrent mental health problems and problematic substance use common during COVID-19, with identifiable risk factors.
Cannabis use disorder linked to suicidal ideation in rural Maryland ER visits ↗
Rural Maryland ER data linked cannabis use disorder to 2.7x higher odds of suicidal ideation, though depression and other substance disorders carried stronger associations.
Cannabis use linked to higher complication rates after breast implant reconstruction ↗
In a study of 243 breast reconstruction patients, 12 active cannabis users had significantly more infections, reoperations, and ER visits, though the small sample size limits conclusions.
Cannabis co-use alters stress responses during nicotine withdrawal ↗
Cannabis-nicotine co-users showed exaggerated blood pressure stress responses and higher cannabis cravings during nicotine withdrawal compared to single-substance users.
Review of medications being tested to treat cannabis use disorder ↗
Review of clinical trials found CB1 receptor agonists like nabilone are the most promising medications for treating cannabis use disorder, though none are yet approved.
Recreational cannabis legalization did not increase prescription stimulant distribution ↗
DEA data showed recreational cannabis legalization did not accelerate the national rise in ADHD stimulant prescriptions across states.
How cannabis affects the gut: from antiemetic benefits to cannabinoid hyperemesis ↗
Review of cannabis and GI health found FDA-approved antiemetic benefits but also links to hyperemesis syndrome in heavy users, questioning whether CHS is truly distinct from cyclic vomiting.
Synthetic cannabinoid AB-FUBINACA damaged memory and hippocampal cells in mice ↗
Mouse study showed the synthetic cannabinoid AB-FUBINACA damaged hippocampal cells and impaired memory through oxidative stress, inflammation, and reduced BDNF and NMDA receptor expression.
Review of health risks and organ damage from synthetic cannabinoids ↗
Review documented how synthetic cannabinoids damage the brain, heart, kidneys, and liver through cannabinoid receptor overactivation and non-cannabinoid targets, far exceeding natural cannabis toxicity.
Prenatal cannabis exposure linked to blunted brain reward response and psychotic-like experiences in youth ↗
ABCD Study data linked prenatal cannabis exposure to blunted brain reward responses and psychotic-like experiences in youth, suggesting dopamine-related circuitry disruption.
Prenatal cannabis exposure associated with small increases in autism and ADHD risk ↗
Meta-analysis linked prenatal cannabis to 30% higher ASD risk. A large cohort study found cannabis use disorder before or during pregnancy associated with 3x higher ASD risk.
Meta-analysis linked prenatal cannabis to small increased risk of birth defects ↗
Meta-analysis of 36 studies and 19+ million subjects found prenatal cannabis linked to 25-33% higher odds of birth defects, though adjusted estimates were smaller.
Review of maternal and newborn adverse outcomes from cannabis use during pregnancy ↗
Review of cohort studies and meta-analyses found cannabis use during pregnancy linked to higher risks of preterm birth, low birth weight, NICU admission, fetal death, and placental complications.
Systematic review finds cannabis entourage effect from terpenes remains unproven ↗
Systematic review found individual cannabis terpenes have exploratory therapeutic benefits, but the synergistic entourage effect with cannabinoids remains unproven.
What Is Cannabinoid Hyperemesis Syndrome? A Patient Guide ↗
A JAMA patient page explaining cannabinoid hyperemesis syndrome, a condition of severe cyclic vomiting caused by chronic cannabis use that often goes undiagnosed for years.
Cannabis use identified as a risk factor for loneliness in two-year study ↗
Two-year Brazilian study found cannabis use associated with 75% higher loneliness risk, the largest effect among clinical factors studied, though the direction of causation is unclear.
Review of cannabinoid treatments for autism spectrum disorder symptoms ↗
Review of cannabinoid treatments for autism found encouraging but mixed evidence from clinical trials, with good safety profiles but not enough data to recommend CBD for ASD.
CBD reduced pain in rats with sex-dependent dose differences across the estrous cycle ↗
Rat study found CBD reduced pain effectively in both sexes, but females in late diestrus responded to doses 10-fold lower than males, suggesting hormonal influence on CBD efficacy.
Cannabis hyperemesis triggered dangerous blood pressure spikes in a patient with adrenal tumor ↗
Case report described how cannabis hyperemesis caused violent retching that compressed a patient's adrenal tumor, triggering dangerous blood pressure spikes requiring ICU care.
Pediatric cannabis ER visits and hospitalizations rose sharply after Massachusetts legalization ↗
Massachusetts data showed a 60% increase in pediatric cannabis ER visits and 126% increase in hospitalizations after recreational legalization, with youngest children most affected.
Canadian medical cannabis registrations declined after recreational legalization ↗
After Canada legalized recreational cannabis, medical registrations dropped but remaining patients bought more per purchase, suggesting casual users left while committed patients stayed.
Brain reward circuit shows reduced dopamine activity during THC withdrawal in rats ↗
Rat study found THC withdrawal reduced dopamine neuron firing in the brain's reward center, with functional changes in the habenula-RMTg circuit that may drive negative withdrawal states.
Depressive symptoms predicted cannabis vaping initiation in college-age young adults ↗
Four-year study of 3,085 college-age adults found depressive symptoms predicted cannabis vaping initiation, with rates doubling from 2017 to 2019.
Cannabis and alcohol were the most common substances among young Black and Latinx sexual minority men ↗
Study of 466 young Black and Latinx sexual minority men found cannabis used by 76%, with polysubstance use linked to higher HIV risk behaviors.
Black cancer patients more likely to view cannabis as more effective than opioids for pain ↗
Survey of 1,220 cancer patients found Black patients less likely to use opioids and 2.5x more likely to view cannabis as more effective, though socioeconomic factors partly explained the difference.
Three patterns of medicinal cannabis use emerged among young LA adults after recreational legalization ↗
Study of LA young adults found 40% of medical cannabis patients used recreationally, with these groups showing increasing mental health symptoms and problematic use over time.
High-potency cannabis use predicted psychosis risk independently of genetic predisposition ↗
Two large studies found daily high-potency cannabis use carried 5x psychosis risk independently of genetic predisposition, and schizophrenia genetics did not predict heavy cannabis use.
Pregnancy hormones likely alter how the body processes THC ↗
Review predicted that pregnancy hormones alter THC metabolism by inducing key liver enzymes, potentially changing how pregnant individuals experience THC effects.
Large study found no link between prenatal cannabis use and child developmental delays ↗
Study of nearly 120,000 pregnancies found no link between early-pregnancy cannabis use and child developmental delays through age 5.5, at any frequency of use.
Large study found no link between prenatal cannabis use and child autism ↗
Study of nearly 179,000 pregnancies found no association between early-pregnancy cannabis use and child autism after adjusting for maternal factors, contrasting earlier studies.
In utero cannabis exposure linked to low birth weight and preterm birth in large study ↗
Study of 365,000 infants found in utero cannabis exposure linked to 20% higher odds of low birth weight and 24% higher odds of being small for gestational age, with dose-response effects.
Little evidence that cannabis harms cognition in people with HIV ↗
Systematic review found little evidence that cannabis harms cognition in people with HIV, with potential anti-inflammatory benefits and effects varying by cognitive domain.
How cannabinoids affect long-term memory formation through synaptic plasticity ↗
Review found cannabinoid effects on memory and synaptic plasticity are contradictory, depending on dose, timing, brain region, and receptor interactions, highlighting biological complexity.
Cannabis use disorder linked to 60% higher cardiovascular disease risk in Canadian adults ↗
Canadian study of 60,000 adults found cannabis use disorder linked to 57% higher risk of cardiovascular events, with stronger relative risk in otherwise healthy individuals.
Cannabis co-use with opioids linked to worse mental health but not worse pain in Black adults ↗
Study of 401 Black adults found cannabis-opioid co-use linked to worse mental health and opioid dependence but not worse pain, challenging assumptions about cannabis as an opioid complement.
Methadone patients had lower cannabis use than buprenorphine patients in opioid treatment trial ↗
Trial found methadone patients had 53% lower odds of cannabis-positive urine than buprenorphine patients, but cannabis use did not affect opioid treatment outcomes.