Potent Cannabis Products Linked to Psychosis, Mental Health Risks
For depression and anxiety, though, review finds mixed results
Shannon Firth
Published by MedPage Today on August 25, 2025
Cannabis products containing high concentrations of delta-9-tetrahydrocannabinol (THC) — the main psychoactive compound in marijuana — were linked to psychosis, schizophrenia, and addiction, a systematic review found.
Across 99 studies examining the effects of high-concentration THC products on mental health outcomes, 70% of the nontherapeutic studies (i.e., those not attempting to treat a medical condition or symptom) showed an unfavorable association with psychosis or schizophrenia and 75% found a relationship to cannabis use disorder (CUD).
Anxiety and depression appeared to be worsened in 53% and 41% of such studies, respectively, with even higher rates when studying healthy individuals specifically, reported Jonathan M. Samet, MD, of the Colorado School of Public Health in Aurora, and co-authors, writing in the Annals of Internal Medicine.
The findings complement those of prior systematic reviews “reinforcing the conclusion that higher THC concentrations increase the risk for adverse mental health outcomes, particularly for psychosis or schizophrenia (in both healthy persons and those with preexisting psychosis) and CUD.
-Richard J Baum, ONDCP, Senior Policy Analyst, Emerging Threats
