Sex differences and Cognitive Processing therapy for PTSD in Serious Mental illness

Objective: The goal of the study was to examine sex differences in clinical presentation and treatment outcomes in a pilot test of the effectiveness of Cognitive Processing Therapy (CPT) for the treatment of Posttraumatic Stress Disorder (PTSD) in Serious Mental Illness (SMI). The study represents a secondary analysis of a previously published CPT trial (Nishith et al., 2024). Method: An open pilot trial was conducted at a certified community behavioral health center with 50 total participants. Participants who met diagnostic criteria for major depressive, bipolar, or psychotic disorders were assigned to CPT which comprised of 12 individual weekly therapy sessions and included education about trauma and PTSD, emotional processing of the trauma, and cognitive restructuring of trauma-related stuck point beliefs, with specific focus on safety, trust, control, esteem, and intimacy. Results: Of the 50 participants who volunteered for the study, 40 started CPT, 27 (67.5 %) completed therapy and 13 (32.5 %) dropped out. Data on 3 trans -gender male completers were screened out. Also, data on one drop-out with an atypical index trauma (incarceration) was also screened out. The final intent to treat (ITT) sample thus comprised of 36 clients, 24 completers and 12 dropouts. Data on the PCL-5 and PHQ-9 were carried forward from pre- to post-treatment for the 12 dropouts (LOCF; Resick et al., 2002). Results demonstrated that both men and women showed a higher prevalence of sexual assault as compared to physical assault or loss of a near one to murder, suicide, or illness. The PTSD symptom scores for interpersonal trauma (sexual assault, and physical assault) were significantly greater as compared to non-interpersonal trauma (loss of a near one to murder, suicide, or illness) at pre-treatment. Men showed significantly greater scores than women on depression for non-interpersonal trauma. In contrast, women showed significantly greater scores than men on depression for the interpersonal trauma of sexual assault but not physical assault. The intent to treat analyses showed that men as well as women demonstrated statistically significant decreases, with CPT, in PTSD and depression symptoms for both non-interpersonal trauma and interpersonal trauma. Conclusion: Results demonstrate promising evidence of CPT in addressing PTSD and depression for both men and women with a SMI irrespective of initial clinical presentation.