Meta-Analysis of the Treatment of Posttraumatic Stress Disorder in Adults With Comorbid Severe Mental Illness

Objective: To evaluate the efficacy of psychosocial treatments for posttraumatic stress disorder (PTSD) among individuals with a comorbid severe mental illness (SMI; ie, schizophrenia, bipolar disorder, major depressive disorder). Data Sources: PubMed, PsycINFO, CINAHL, and Cochrane Library were searched from January 1998 to March 2020 using keywords related to PTSD, treatment, and severe mental illness. Study Selection: All clinical trials for PTSD psychotherapy among individuals with SMI were included. From 38 potentially eligible studies, a total of 14 clinical trials across 684 individuals with comorbid SMI and PTSD were identified and included in the analysis. Data Extraction: Data on demographic, SMI diagnosis, symptom severity, sample attrition, and treatment protocol received were extracted. Effect size calculations and subsequent meta-analyses were conducted using the Meta-Analysis Package for R (metafor) version 2.1-0 in R (3.6.0). Results: PTSD treatments had a large effect on PTSD outcomes among individuals with SMI, with patients experiencing a standard deviation reduction in PTSD symptomatology pre- to post-treatment (g = -1.009, P < .001, k = 34). Prolonged exposure (g = -1.464; P < .001; SE = 0.276; k = 5), eye movement desensitization and reprocessing (g = -1.351; P < .001; SE = 0.276; k = 5), and brief treatment program (g = -1.009; P < .001; SE = 0.284; k = 5) had the largest effects on PTSD symptoms. Conclusions: Although underrepresented in the PTSD literature, PTSD psychotherapies are effective for individuals with SMI. Treatments with an exposure-based component may have greater efficacy in this clinical population.