Treatment for co-occurring posttraumatic stress disorder and substance use disorders among veterans and civilians: A test of causally moderated comparative effectiveness.

OBJECTIVE: The prevalence and negative sequelae of co-occurring posttraumatic stress disorder and substance use disorder (PTSD + SUD) are well documented. Findings from evidence syntheses regarding which PTSD + SUD treatments work best overall have been mixed, potentially because these treatments are not equally effective for all PTSD + SUD patient subgroups. Epidemiological and qualitative research suggest that veteran status may be related to differential PTSD + SUD treatment response. This study, applying recent quantitative methodological advances in evidence synthesis, is the first to examine the potential moderating effect of veteran status on PTSD + SUD treatment outcome. METHOD: We report secondary analyses of psychotherapy arm data (k = 26 randomized controlled trials; n = 3,228) from Project Harmony, a meta-analysis of individual PTSD + SUD patient data from sociodemographically diverse samples incorporating propensity score weighting and integrative data analysis. Outcome models (examined separately for harmonized indicators of latent PTSD, alcohol use, and drug use severity) were fit under propensity score weighting multilevel modeling. RESULTS: Tests of causally moderated comparative effectiveness showed that trauma-focused psychotherapy targeting PTSD and integrated trauma-focused psychotherapy targeting PTSD and SUD were both superior to treatment as usual for alcohol use severity outcomes, and this effect was stronger for veterans than civilians. Analyses did not provide evidence for differential response to active PTSD + SUD psychotherapies, relative to treatment as usual, on PTSD or drug use severity outcomes as a function of veteran status. CONCLUSIONS: Findings lend support for delivering trauma-focused psychotherapies to patients with PTSD + SUD, especially veterans, and point to important future directions for inquiries into optimizing patient matching to PTSD + SUD treatment. (PsycInfo Database Record (c) 2025 APA, all rights reserved).