(PS4-B31) Impact of Military Sexual Trauma on PTSD Symptom Presentation and Treatment Outcomes in Two Cpt-based Intensive Treatment Programs for Veterans

Intensive treatment programs (ITPs), in which evidence-based treatments are delivered daily over two to three weeks, have shown to be effective treatments of posttraumatic stress disorder (PTSD). To date, most Cognitive Processing Therapy (CPT) research has focused on the impact of trauma type and pre- to post-treatment change in overall PTSD symptom severity; however, PTSD symptom presentations may differ depending on the type of trauma experienced and symptoms may not change at the same rates throughout treatment. Understanding how trauma type and clinical variables impact treatment outcomes would allow for further personalization of treatment in ITPs. The present study examined whether experiencing military sexual trauma (MST) impacts reductions in PTSD total and cluster symptom severity at pre-, mid-, and post-treatment in 3- or 2-week CPT-based ITPs for veterans with PTSD.                                     

Data were drawn from two samples to internally replicate results: veterans who completed a 3- (n = 487) or a 2-week CPT-based ITP for PTSD (n = 278). Trauma grouping was coded based on endorsement of MST. Self-reported PTSD symptom severity (PCL-5) was assessed pre-, mid-, and post-treatment and used to calculate total and cluster level change scores. Cluster scores were calculated by summing PCL-5 items to create subscales reflecting the four-factor model (i.e., intrusions, avoidance, alterations in cognitions/mood, and hyperarousal). Linear regression models were then used to examine if MST predicted changes in PTSD total and cluster symptom severity from pre- to mid-, and pre- to post-treatment, accounting for age and sex. 

Veterans reported significantly lower levels of PTSD symptom severity after treatment, (3-week: MST d = 1.21, non-MST d = 1.36; 2-week: MST d = 1.21, non-MST d = 1.39, all ps < .001). Results showed that there were no significant differences in changes in total PTSD symptom severity (3-week: B = 1.86, r² = .00; 2-week: B = 3.10, r² = .01, all ps > .05) or cluster level (3-week: Bs = -.01-1.07, r² = -.01-.01; 2-week: Bs = .12-2.96, r² = .00-.01, all ps > .05) from pre- to mid-treatment by trauma type. There were no significant differences in improvements of veterans total PTSD symptom severity (3-week: B = .92, r² = .00; 2-week: B = 4.48, r² = .01, all ps > .05) or cluster level (3-week: Bs = .05-.26, r² = -.01-.02; 2-week: Bs = .12-2.96, r² = .00-.01, all ps > .05) from pre- to post-treatment by trauma type.

Results of this study indicate the robust reductions in veterans’ PTSD symptom severity after completion of the ITPs, regardless of MST status, as it was not associated with changes in PTSD total or cluster symptom severity. Additionally, rates of improvement did not differ by trauma type. These results suggest CPT-based ITPs appear to be equally effective for individuals who have and have not experienced MST. However, to further improve understanding of differences in treatment outcomes in ITPs for PTSD, future research should attempt to identify and test alternate factors that may predict changes in total PTSD and cluster symptom severity.