# Review of Cannabinoid Clinical Trials for Mental Health Treatment > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/cannabinoid-clinical-trials-mental-health-treatment-review/ > **Published:** 2026-03-26T20:25:51-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T11:03:19-04:00 > **Clinical Summary:** Explore cannabinoid clinical trials mental health treatment review focusing on efficacy, safety, and adverse effects in mental health disorders. --- #### Clinical Takeaway Based on randomized controlled trials, the current evidence does not firmly establish cannabinoids as effective primary treatments for mental disorders or [substance use disorders](https://cedclinic.com/cannabinoid-clinical-trials-mental-disorders-evidence-2/). Adverse effects were consistently reported across studies, underscoring the importance of careful clinical monitoring when cannabinoids are used in these populations. ### #1 The efficacy and safety of cannabinoids for the treatment of mental disorders and substance use disorders: a systematic review and meta-analysis. **Citation:** Wilson Jack et al. *The efficacy and safety of cannabinoids for the treatment of mental disorders and substance use disorders: a [systematic review](https://cedclinic.com/cannabinoid-safety-efficacy-mental-health-study/) and meta-analysis.* The lancet. Psychiatry. 2026. PMID: 41856154. **Study type:** Journal Article, Systematic Review, Meta-Analysis  |  **Topic area:** Autism  |  **CED Score:** 15 Design: 6 Journal: 4 N: 0 Recency: 3 Pop: 3 Human: 1 Risk: -2 **Quality Gate Alerts:** - Preclinical only **Abstract:** BACKGROUND: Mental disorders and substance use disorders (SUDs) are among the leading reasons for which the medical use of cannabinoids has been approved, but their efficacy and safety in treating these conditions is yet to be established. We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) testing the efficacy and safety of cannabinoids as the primary treatment for mental disorders or SUDs. METHODS: We searched Ovid MEDLINE, PsychINFO, Cochrane Central Register of Controlled [Clinical Trials](https://cedclinic.com/endocannabinoid-system-emotional-memory-ptsd-treatment/), Cochrane Database of Systematic Reviews, and Embase for peer-reviewed articles published between Jan 1, 1980, and May 13, 2025, evaluating the efficacy of cannabinoids in reducing or treating mental disorders and SUDs as the primary indication. Primary outcomes were remission of disorder or reduction in disorder symptoms. Safety was assessed via synthesis of all-cause and serious adverse events, which was used to calculate the number needed to treat to harm (NNTH). Two independent reviewers screened all studies and performed data extraction. Evidence was synthesised as odds ratios (ORs) for dichotomous measures and standardised mean differences (SMDs) for continuous measures, via random-effects meta-analysis in Review Manager, version 5.4. Risk of bias was assessed using the Cochrane Collaboration Risk of Bias 2.0 tool. We evaluated the quality of the primary outcomes using the GRADE framework. The study was registered with PROSPERO (CRD42023392718). FINDINGS: 54 trials were identified for inclusion (2477 participants; 1713 [69%] males, 764 [31%] females; median age 33·3 years [IQR 28·1-38·05; ethnicity data not available). 24 (44%) of these trials had a high risk of bias, and the certainty of evidence for most outcomes was low. Our meta-analysis revealed that a combination of cannabidiol and delta-9-tetrahydrocannabinol reduced [cannabis withdrawal symptoms](https://cedclinic.com/cannabis-use-disorder-risk-clinical-evidence/) (SMD -0·29, 95% CI -0·57 to -0·02) and weekly grams of [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/) (-1·00, -1·69 to  |  [View on PubMed ↗](https://pubmed.ncbi.nlm.nih.gov/41856154/)[DOI ↗](https://doi.org/10.1016/S2215-0366(26)00015-5) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) Physician-Led, Whole-Person Care A doctor who takes the time to truly understand you. Personal care that starts with listening and is guided by experience and ingenuity. Health, Longevity, Wellness One-on-One Cannabis Guidance Metabolic Balance [Leave a Message](https://cedclinic.com/contact/) [Metabolic Care](https://cedclinic.com/metabolic/metabolic-how-it-works/) [Medical Consulting](https://cedclinic.com/book/) [Cannabis Care](https://cedclinic.com/book/) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) RELATED READING AT CED CLINIC Continue exploring the evidence [Cannabinoid Clinical Trials for Mental and Substance Use Disorders](https://cedclinic.com/cannabinoid-clinical-trials-mental-disorders-safety-review/) A comprehensive overview of cannabinoid clinical trials addressing both mental health and substance use disorders, highlighting key findings and safety considerations. [Read More](https://cedclinic.com/cannabinoid-clinical-trials-mental-disorders-safety-review/) [Cannabinoid Clinical Trials: Mental Health Evidence Review](https://cedclinic.com/cannabinoid-clinical-trials-mental-health-evidence-review/) An evidence review focusing on the outcomes and quality of cannabinoid clinical trials related to mental health conditions. [Explore Review](https://cedclinic.com/cannabinoid-clinical-trials-mental-health-evidence-review/) [Cannabinoid Clinical Trials: Mental Health & Addiction Review](https://cedclinic.com/cannabinoid-clinical-trials-mental-health-substance-use-treatment/) This review examines clinical trial data on cannabinoids for mental health and addiction, emphasizing efficacy and safety profiles. [Learn More](https://cedclinic.com/cannabinoid-clinical-trials-mental-health-substance-use-treatment/) Have thoughts on this? 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