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 who report cannabis use alongside alcohol or 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 addresses a critical clinical gap by examining whether evidence-based trauma-focused treatments maintain efficacy in the substantial subset of PTSD+SUD patients who use cannabis, a population often excluded from or underrepresented in traditional trials. The findings directly inform treatment selection and patient counseling for comorbid PTSD and substance use disorders, where cannabis use prevalence is high but treatment outcome data remain limited. Understanding differential treatment response in cannabis users versus non-users allows clinicians to optimize intervention strategies for this complex, prevalent 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 an important clinical gap by examining trauma-focused treatment outcomes in patients with co-occurring PTSD, cannabis use, and other substance use disorders, several limitations warrant careful interpretation. The analysis draws from only four of the 36 available RCTs in Project Harmony, potentially introducing selection bias and reducing statistical power to detect meaningful differences; additionally, cannabis use patterns, potency, and frequency were likely heterogeneous across trials and inadequately characterized. The generalizability to real-world populations is further constrained by the structured nature of RCTs, which typically exclude patients with active intoxication, severe polysubstance use, or untreated psychiatric comorbidities—populations commonly seen in clinical practice. These confounders notwithstanding, the study usefully explores whether evidence-based trauma interventions retain efficacy in this vulnerable population, suggesting that clinicians should not reflexively deprioritize trauma-focused therapy in patients actively using cannabis. In practice, concurrent cannabis use should prompt enhanced screening