LAUSR

Abstract Background: Cognitive processing therapy (CPT) is an effective treatment for posttraumatic stress disorder (PTSD), including for veterans with military sexual trauma (MST)-related PTSD. Most CPT research to date has focused on pre- to post-treatment change in total PTSD symptoms; however, PTSD symptom criteria may not change equivalently over the course of treatment. For example, changes in re-experiencing symptoms have been shown to precede changes in other PTSD criteria during other PTSD treatments (i.e. virtual reality exposure therapy, venlafaxine ER). An improved understanding of the mechanism of change in PTSD symptoms during CPT may assist in optimizing treatment. Aims: The purpose of this study was to identify the pattern and temporal precedence of change in PTSD symptom criteria during and after CPT using cross-lagged panel analyses. Method: Data from veterans (n = 32) enrolled in a randomized clinical trial investigating the effectiveness of CPT for MST-related PTSD were utilized for this secondary analysis. Using hierarchical linear modelling, each symptom criterion was entered as a predictor of subsequent change in the other PTSD symptom criteria. Results: All symptom criteria followed a logarithmic pattern of change. Hyperarousal symptoms were found to both predict and temporally precede change in avoidance symptoms, but not re-experiencing symptoms. Re-experiencing and avoidance symptoms did not predict change in other PTSD symptom criteria. Conclusions: These findings provide initial support that targeting and reducing hyperarousal symptoms may be a key component of PTSD intervention with CPT. Additional research is needed to identify factors that predict change in PTSD-related re-experiencing symptoms.