Clinical Takeaway
Trauma-focused therapy remains effective for PTSD even in patients who use cannabis, including those with co-occurring substance use disorders. Patients should not be excluded from or delayed in receiving evidence-based PTSD treatment on the basis of cannabis use alone.
#6 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 a critical clinical gap by examining whether evidence-based trauma treatments maintain efficacy in the substantial subset of PTSD patients who use cannabis, particularly those with concurrent substance use disorders. The findings clarify treatment selection and outcome expectations for a high-risk, high-prevalence population that is frequently excluded from or underrepresented in PTSD treatment trials. These results have immediate implications for clinical decision-making regarding trauma-focused interventions in patients with comorbid PTSD and cannabis or polysubstance 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 examining trauma-focused treatment outcomes in patients with co-occurring PTSD, cannabis use, and other substance use disorders addresses a clinically relevant question, yet several important limitations warrant caution in interpretation. The analysis draws from only four RCTs within a larger Project Harmony dataset, which may limit statistical power and generalizability, particularly given the heterogeneity of cannabis use patterns, dosing, and frequency across populations. The abstract does not clarify whether cannabis use was a primary focus or secondary variable of interest, whether active cannabis intoxication during treatment was controlled for, or how cannabis legality and access varied across trial sites, all of which could meaningfully influence treatment engagement and outcomes. Despite these caveats, the study’s attention to this high-risk, understudied population is valuable; clinicians should consider that current evidence does not support cannabis as an adjunct to trauma-focused therapy for PTSD, and patients presenting with this comorbidity may benefit from integrated, structured treatment addressing both PTSD