Systematic Review Finds High-Potency Cannabis Linked to Problem Use, But Evidence Is Very Low Quality

Of 42 eligible studies, most addressed mental health, problematic cannabis use, and other substance use. Findings in the problematic cannabis use domain were suggestive of an association with higher-potency cannabis. Findings in other domains were less consistent but tended toward poorer outcomes with higher potency. Therapeutic outcomes were limited and mixed. Overall GRADE certainty: "very low."

Systematic review of five databases. Developed ecologically relevant potency categories: 1-9%, 10-19%, 20-30%, kief/resin (~30-50%), concentrates (60%+). Two independent reviewers for screening, extraction, and quality. GRADE framework for evidence certainty.

THC concentrations in cannabis have risen continuously, yet the health impact of high-potency products is poorly understood. This review from the American Journal of Psychiatry provides the most comprehensive assessment to date and finds the evidence base is alarmingly thin.

Policy discussions about potency caps and product regulation are happening with very limited evidence. This review highlights the urgent need for prospective studies, especially on cardiovascular, cancer, and prenatal outcomes, before evidence-based potency policies can be established.

Most included studies were cross-sectional. Few studies examined health outcomes beyond mental health and problem use. Potency measurement methods varied. "Very low" certainty limits confidence in all findings.