# Cannabinoid Clinical Trials: PTSD and Substance Use Disorders > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/ptsd-substance-use-cannabis-trials-clinical-evidence/ > **Published:** 2026-03-11T09:22:43-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T11:59:31-04:00 > **Clinical Summary:** Explore clinical evidence from PTSD substance use cannabis trials showing trauma-focused treatments remain effective despite cannabis use. --- #### Clinical Takeaway People with PTSD and co-occurring substance use disorders who use cannabis can still benefit meaningfully from trauma-focused treatments, and cannabis use does not appear to undermine treatment outcomes compared to non-users. Clinicians should not withhold or delay evidence-based trauma-focused care for patients on the basis of cannabis use alone. ### #5 Cannabis use and trauma-focused treatment for co-occurring posttraumatic stress disorder and substance use disorders: A meta-analysis of individual patient data. **Citation:** Hill Melanie L et al. *Cannabis use and trauma-focused treatment for co-occurring posttraumatic stress disorder and substance use disorders: A meta-analysis of individual patient data.* Journal of [anxiety disorders](https://cedclinic.com/adolescent-cannabis-use-and-anxiety-research/). 2024. PMID: 38266511. **Study type:** Meta-Analysis, Journal Article, Research Support, N.I.H., Extramural  |  **Topic area:** Anxiety & PTSD  |  **CED Score:** 12 Design: 6 Journal: 0 N: 4 Recency: 1 Pop: 2 Human: 1 Risk: -2 Why This Matters This meta-analysis provides critical evidence on whether trauma-focused treatments maintain efficacy in the clinically common but understudied population of patients with co-occurring [PTSD and cannabis](https://cedclinic.com/cannabis-use-anxiety-young-sexual-minority-women/) use, informing treatment selection and patient counseling in dual-diagnosis settings. The findings directly address a major clinical gap: whether concurrent cannabis use should modify treatment recommendations or be considered a barrier to standard evidence-based PTSD interventions. Understanding these treatment outcomes is essential for optimizing clinical protocols and managing expectations in patients who present with both PTSD and active substance use. **Quality Gate Alerts:** - Preclinical only **Abstract:** High rates of cannabis use among people with posttraumatic stress disorder (PTSD) have raised questions about the efficacy of evidence-based PTSD treatments for individuals reporting cannabis use, particularly those with co-occurring alcohol or other substance use disorders (SUDs). Using a subset of four randomized [clinical trials](https://cedclinic.com/endocannabinoid-system-emotional-memory-ptsd-treatment/) (RCTs) included in Project Harmony, an individual patient meta-analysis of 36 RCTs (total N = 4046) of treatments for co-occurring PTSD+SUD, we examined differences in trauma-focused (TF) and non-trauma-focused (non-TF) treatment outcomes for individuals who did and did not endorse baseline cannabis use (N = 410; 70% male; 33.2% endorsed cannabis use). Propensity score-weighted mixed effects modeling evaluated main and interactive effects of treatment assignment (TF versus non-TF) and baseline cannabis use (yes/no) on attendance rates and within-treatment changes in PTSD, alcohol, and non-cannabis drug use severity. Results revealed significant improvements across outcomes among participants in all conditions, with larger PTSD symptom reductions but lower attendance among individuals receiving TF versus non-TF treatment in both cannabis groups. Participants achieved similar reductions in alcohol and drug use across all conditions. TF outperformed non-TF treatments regardless of recent cannabis use, underscoring the importance of reducing barriers to accessing TF treatments for individuals reporting cannabis use. Clinical Perspective This meta-analysis addresses a clinically relevant question about whether cannabis use compromises outcomes in trauma-focused psychotherapies for patients with co-occurring PTSD and substance use disorders, drawing on individual patient data from four RCTs nested within a larger evidence synthesis. While the structured approach and individual-level analysis represent methodological strengths, the small subset of four trials examining cannabis specifically may limit generalizability to diverse patient populations and cannabis use patterns, and the analysis cannot fully disentangle whether cannabis use itself impairs treatment response or whether it serves as a marker for greater symptom severity and treatment complexity. The meta-analytic design also lacks granularity regarding cannabis potency, frequency, timing relative to therapy, and whether patients were actively using or attempting abstinence during treatment. Clinically, these data suggest that cannabis use should not automatically be viewed as a contraindication to evidence-based trauma therapy, though providers should individualize assessment of whether active use is interfering with treatment engagement and consider addressing cannabis use motivationally or struct  |   |  Further Reading CED Clinic Blog[Cannabis-Infused Beverages as Alcohol Alternatives: New York at Five Years](https://cedclinic.com/cannabis-beverage-substitution-alcohol-new-york-five-years/) Research Digest[Daily Digest 2026-03-07](https://cedclinic.com/adolescent-cannabis-psychiatric-outcomes-2026-digest/) Cannabis Policy Wire[Policy Watch: 20 Regulatory Updates — March 10, 2026](https://cedclinic.com/dea-scheduling-synthetic-opioids-regulatory-updates-2026/) [View on PubMed ↗](https://pubmed.ncbi.nlm.nih.gov/38266511/)[Full Text ↗](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11138203/)[DOI ↗](https://doi.org/10.1016/j.janxdis.2024.102827) [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: Cannabis for PTSD and SUD](https://cedclinic.com/cannabis-use-trauma-focused-treatment-ptsd-sud-outcomes/) Review detailed [clinical trials](https://cedclinic.com/endocannabinoid-system-emotional-memory-ptsd-treatment/) exploring cannabis use in PTSD and substance use disorder treatment outcomes. [Read More](https://cedclinic.com/cannabis-use-trauma-focused-treatment-ptsd-sud-outcomes/) [Cannabinoid Clinical Trials: PTSD and Substance Use Disorder](https://cedclinic.com/cannabis-use-trauma-focused-treatment-ptsd-sud-outcomes/) Explore research findings on cannabinoid clinical trials focused on PTSD and substance use disorder populations. [Explore Research](https://cedclinic.com/cannabis-use-trauma-focused-treatment-ptsd-sud-outcomes/) [Cannabis in PTSD Treatment: Meta-Analysis of Trauma-Focused Care](https://cedclinic.com/cannabis-use-ptsd-treatment-outcomes-meta-analysis/) Analyze meta-analytic data on the role of cannabis in trauma-focused [PTSD treatment](https://cedclinic.com/cannabis-and-ptsd-treatment-memory-loss-benefits/) effectiveness. [Learn More](https://cedclinic.com/cannabis-use-ptsd-treatment-outcomes-meta-analysis/) Have thoughts on this? Share it: [X Share on X](https://twitter.com/intent/tweet?text=Cannabinoid%20Clinical%20Trials%3A%20PTSD%20and%20Substance%20Use%20Disorders&url=https%3A%2F%2Fcedclinic.com%2Fptsd-substance-use-cannabis-trials-clinical-evidence%2F) [in Share on LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fcedclinic.com%2Fptsd-substance-use-cannabis-trials-clinical-evidence%2F) [Share on BlueSky](https://bsky.app/intent/compose?text=Cannabinoid%20Clinical%20Trials%3A%20PTSD%20and%20Substance%20Use%20Disorders%20https%3A%2F%2Fcedclinic.com%2Fptsd-substance-use-cannabis-trials-clinical-evidence%2F) [Follow on Instagram](https://www.instagram.com/drbenjamincaplan) [Read more on Substack](https://doctorapprovedcannabis.substack.com/) [Subscribe via RSS](https://cedclinic.com/feed/) ### Related --- ### Verification & Medical Governance - **Lead Clinical Author:** Benjamin Caplan, MD - **Credentials:** Board Certified in Family Medicine (ABFM), Former CMO Canna Care Docs (250,000+ patients supervised), Founder & CMO CED Clinic & CED Foundation, Author of *The Doctor-Approved Cannabis Handbook* (Penguin Random House). - **Clinical Scale:** 350,000+ lifetime evaluations overseen; 81,008-patient Real-World Evidence Registry (`~/.ced_rwe_vault.db`); 125,000+ peer-reviewed study literature observatory (`http://localhost:8768/api/explorer/terminal`). - **License Verification:** Commonwealth of Massachusetts License #240562 (https://checkahealthlicense.mass.gov/). - **NPI Registry:** 1962722637 (https://npiregistry.cms.hhs.gov/provider-view/1962722637). - **Ethics & Data Privacy:** Clinical registry observations adhere strictly to HIPAA Safe Harbor de-identification (45 CFR § 164.514(b)) and criteria for secondary research exemption under 45 CFR § 46.104(d)(4).