Browse more cannabis research, findings, methods, and limitations.
CBD given to adolescent mice produced lasting changes in adult behavior including reduced social activity and anxiety, and worsened THC sensitivity in mice carrying a schizophrenia risk gene.
CBD reduced facial nerve pain consistently in both male and female rats without motor impairment, working through anti-inflammatory and antioxidant mechanisms in pain pathways — outperforming carbamazepine on consistency.
Among 822 adults with anxiety or depression, social support reduced medical cannabis use for non-disabled individuals but not for those with disabilities, suggesting disabled individuals use cannabis for needs beyond what social support provides.
People with hypersomnolence disorders used cannabis at nearly double the general population rate in the Netherlands, with most current users reporting symptom improvement — providing rationale for clinical trials.
A pharmacist-focused review examines medical marijuana's therapeutic benefits alongside its effects on developing brains, highlighting the pharmacist's essential role in patient counseling.
In 526 young adults tracked through emerging adulthood, cannabis use increases predicted more binge drinking at ages 18–21 but less binge drinking by ages 24–25, revealing an age-dependent relationship.
On 15% of college students' drinking days, they combined alcohol with both cannabis and energy drinks — the riskiest pattern, associated with the heaviest drinking and most negative consequences.
In 11,036 adolescents, cannabis use onset altered cognitive development trajectories—and hair testing showed THC and CBD had different effects on cognition.
In young cannabis users, plasma THC metabolite concentration was the only measure — over self-report, urine, hair, or oral fluid — that predicted depression symptoms, suggesting blood testing may reveal hidden clinical risks.
The ABCD Study found 7.1% of U.S. 15–16-year-olds had biochemically verified heavy cannabis use, with self-report matching hair tests only 45% of the time — suggesting major underreporting in teen surveys.
Nearly 3% of U.S. adolescents have been given CBD for health reasons, with large racial disparities and strong links to mental health symptoms and sleep problems in the ABCD Study.
Newborn rats given CBD showed lasting reductions in brain cell branching in both sexes, with females developing spatial memory deficits in adulthood — raising safety concerns about early-life CBD exposure.
Cannabis use among Canadians aged 55–65 jumped from 19% to 25% after legalization, with many using it for health conditions — calling for age-targeted education about medication interactions.
A German real-world study found a 1:1 THC:CBD cannabis extract reduced chronic pain from 5.5/10 to 3.4/10, with cannabis-naïve patients seeing even larger drops (5.9 to 2.4).
A double-blind RCT found that CBD gel applied to jaw muscles nightly for 30 days significantly improved sleep quality and reduced migraine disability in bruxism patients, with 10% CBD showing the strongest effects.
A systematic review found CBD effective for chronic jaw and facial muscle pain (TMD, bruxism) especially when applied topically, but not consistently helpful for acute dental pain — clarifying where CBD works best.
A nonjudgmental two-session cannabis intervention for young adults with psychosis achieved 92% completion and universal recommendation, supporting its feasibility for a larger efficacy trial.
Among heavy cannabis-using young adults, higher 2-AG endocannabinoid levels correlated with better memory while higher AEA levels correlated with worse performance, suggesting individual biology shapes cognitive vulnerability.
A 30-year French study found 16% of cannabis users maintained persistent use from adolescence to their mid-40s, predicted by childhood academic struggles, family conflict, and early initiation.
Among 420 teen cannabis users, using multiple product types (flower, concentrates, edibles) was the strongest predictor of cannabis use disorder at 6 months — stronger than any single product type.
Among 141 UK young adults who co-used tobacco and cannabis, quitting one substance was strongly linked to quitting the other — but almost no one used formal cessation support for either.
HIV-positive immune cells showed higher inflammatory gene activity, and cannabis use was associated with lower levels — but CBD treatment produced unexpectedly complex effects on downstream inflammatory signaling.
Activating cannabinoid receptors in an autism rat model reduced repetitive behaviors and social deficits while restoring disrupted brain lipid profiles to near-normal, linking the endocannabinoid system to ASD metabolic dysfunction.
Among 157,500 California students, 75% had heard about vaping lung injuries but only 11% correctly identified cannabis vapes as the cause — most blamed nicotine, highlighting a critical gap in health communication.
Machine learning identified two endocannabinoid-related genes with reduced expression in depression patients, validated as potential diagnostic biomarkers with a predictive nomogram for MDD risk.
A machine learning model using just five factors — sex, delinquency, and three personality traits — predicted cannabis use disorder within 5 years of first use, validated across three datasets.
The gateway effect is bidirectional: cannabis predicts starting tobacco, e-cigarettes, and alcohol just as much as those substances predict starting cannabis, with all effects stronger in adolescence.
Among 4,031 young adults, friends' and parents' cannabis use directly increased use behavior, while advertising worked mainly through changing risk perceptions and motives — all three reduced perceived harm.
A review maps the bidirectional communication between gut bacteria and the body's endocannabinoid system, showing how this axis influences inflammation, mood, and metabolic health across multiple conditions.
Machine learning found 13 factors across 6 domains predicted teens trying cannabis for the first time, but only 4 factors — including cannabis outlet density and home alcohol access — predicted escalation to weekly use.
Nearly 1.6 million cannabis use disorder cases were identified in U.S. mental health facilities over 10 years, peaking in 2018, with depression co-occurring in 30% and 60% of patients being male.
A review finds the endocannabinoid system can both lower eye pressure and protect nerve cells in glaucoma, potentially offering the dual action that no current treatment provides.
A geriatric primary care clinic embedded a medical cannabis program—providing 144 supervised visits to older adults navigating cannabis use with complex medical needs.
A survey of 1,003 cancer survivors found no racial disparities in cannabis use or provider discussions — Black patients who used cannabis were actually the most comfortable discussing it with doctors.
Analysis of a cannabis cessation app revealed distinct user profiles: coping-motivated users showed the most problematic use, suggesting digital interventions should personalize content based on why people use cannabis.
THC and CBD directly suppressed the calcium channels essential for sperm activation by progesterone, providing a molecular mechanism for how cannabis may impair male fertility.
National 2023 data showed various marijuana consumption methods were linked to increased coronary heart disease risk, with combined smoking and vaping showing the highest risk levels.
CBD reduced schizophrenia-like symptoms in animals through two pathways: reducing neuroinflammation and modulating serotonin-MAPK signaling.
A rigorous 12-week double-blind trial found that combined CBD/THC gelcaps did not significantly improve sensory neuropathy from chemotherapy compared to placebo — an important negative result in cannabinoid research.
CBD did not cause DNA double-strand breaks in human liver cells at any tested concentration or time point, providing reassuring evidence against previous genotoxicity concerns.
A survey of 208 German CBD consumers found mostly middle-aged women using CBD oil daily for chronic conditions, reporting predominantly positive health effects from over-the-counter products.
Researchers successfully adapted tobacco dependence measures to cannabis, creating a reliable 15-item scale that enables direct comparison of dependence across both substances for the first time.
In nearly 3 million Australian treatment episodes from 2003–2020, cannabis was consistently the top substance driving adolescents and young adults into substance use treatment.
A review of 64 studies found cannabis disrupts reproduction at every stage—from sperm quality to ovulation to placental function to fetal development.
In a Massachusetts ED after cannabis legalization, patients and doctors frequently disagreed about whether cannabis contributed to the visit, revealing a communication gap in emergency cannabis-related care.
In an HIV cohort tracked 2009–2023, increasing cannabis use did not lead to decreasing alcohol or tobacco use, failing to support the popular substitution hypothesis for this population.
CBD, CBN, and THC all killed bacteria responsible for persistent root canal infections, including hard-to-treat biofilms, suggesting cannabinoids could become novel endodontic antimicrobials.
Prenatal cannabis exposure may delay GABA's developmental switch from excitatory to inhibitory—disrupting the precise timing that guides how the fetal brain wires itself.
Among 3,544 young adults in the PATH study, moderate-to-severe pain predicted starting concurrent alcohol and cannabis use — a particularly risky pattern associated with heavier use and more harm.
Among 4,185 young adults who had never used cannabis, those with moderate-to-severe pain were significantly more likely to start — the first study establishing pain as a prospective predictor of cannabis initiation.