Clinical Takeaway
People with PTSD and co-occurring substance use disorders who also use cannabis can still benefit meaningfully from trauma-focused treatments, and cannabis use does not appear to undermine treatment outcomes compared to non-cannabis users. Trauma-focused approaches remain effective for this population, supporting their use as a first-line option even when cannabis use is present alongside other substance use disorders.
#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 directly addresses whether trauma-focused PTSD treatments remain efficacious in patients with concurrent cannabis use, a clinically prevalent comorbidity that is often exclusionary in trials but requires evidence-based guidance in real-world practice. The findings provide empirical guidance on treatment selection and expected outcomes for the substantial population presenting with PTSD, cannabis use, and additional substance use disorders, where current clinical protocols are largely informed by extrapolation rather than direct evidence. Understanding treatment efficacy across cannabis use patterns informs whether trauma-focused interventions should be modified, sequenced differently, or combined with additional interventions for this high-burden patient population.
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.
🧠 While this meta-analysis addresses a clinically important question about whether trauma-focused treatments remain effective for patients with comorbid PTSD, cannabis use, and other substance use disorders, several limitations warrant careful interpretation. The analysis draws from only four RCTs nested within a larger dataset, which substantially reduces statistical power and generalizability compared to the full Project Harmony cohort, and the abstract does not clarify whether baseline cannabis use severity, frequency, or cannabis use disorder diagnosis was systematically characterized across studies. Additionally, cannabis use patterns have shifted considerably over the past two decades in potency and product types, so findings from older trials may not reflect the current clinical landscape that providers encounter today. The heterogeneity of trauma-focused treatments and concurrent substance use interventions across trials introduces further complexity in isolating cannabis-specific effects. Clinically, while awaiting full results, practitioners should continue offering evidence-based trauma-focused therapies to patients with PTSD and cannabis use, while remaining vigilant about monitoring cannabis use patterns during treatment and