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. 2024. PMID: 38266511.
Design: 6 Journal: 0 N: 4 Recency: 1 Pop: 2 Human: 1 Risk: -2
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 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 (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.
🧠 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