Examining the associations between posttraumatic stress disorder symptom clusters across cognitive processing therapy.

Cognitive processing therapy (CPT) is a well-known trauma-focused treatment that aims to generate more adaptive posttrauma cognitions and emotions. Changes in cognitions are theorized to be the mechanism by which CPT leads to improvement in posttraumatic stress disorder (PTSD) symptoms. The present study aimed to explore associations between changes in PTSD symptom clusters during CPT. We hypothesized that early changes in negative alterations in cognitions and mood (NACM) would correlate with later changes in other symptom clusters. Data were collected from 296 veterans participating a 7-week PTSD residential treatment program at a U.S. Veterans Affairs medical center. PTSD symptoms were assessed at pretreatment (Week 1), midtreatment (Week 4), and posttreatment (Week 7). Cross-lagged path analyses demonstrated that pretreatment-to-midtreatment improvement in NACM was correlated with midtreatment-to-posttreatment improvement in avoidance, β = .52, though this association was bidirectional, suggesting pretreatment-to-midtreatment improvements in either cluster may be correlated with midtreatment-to-posttreatment improvements. Similarly, pretreatment-to-midtreatment improvement in intrusions, β = .40, and arousal, β = .49, were correlated with later improvement in avoidance, suggesting avoidance may improve after improvement in other clusters. Interestingly, pretreatment-to-midtreatment arousal improvement was significantly correlated with midtreatment-to-posttreatment NACM improvement, β = .27, though the reverse was nonsignificant, whereas a bidirectional association between arousal and intrusions emerged, β = .34, β = .53. Early changes in arousal were correlated with later changes in several other symptom clusters, whereas other clusters demonstrated bidirectional associations. These results may inform understanding of symptom improvement timing across CPT, which may aid in treatment selection and planning.