Temporal Sequencing of Change in Posttraumatic Cognitions and PTSD Symptom Reduction During Prolonged Exposure Therapy.

Prolonged exposure (PE) effectively reduces negative cognitions about self, world, and self-blame associated with posttraumatic stress disorder (PTSD), with changes in posttraumatic cognitions being associated with reductions in PTSD symptoms (Foa & Rauch, 2004). Further, recent research has demonstrated that cognitive change is a likely mechanism for PTSD symptom reduction in PE (Zalta et al., 2014). The present study examines temporal sequencing of change in three domains of posttraumatic cognitions (i.e., negative cognitions about the self, negative cognitions about the world, and self-blame) and PTSD symptoms during the course of PE. Adult outpatients meeting diagnostic criteria for PTSD were recruited at 4 sites. Participants (N=46) received 8 sessions of PE over 4 to 6weeks. PTSD symptoms and posttraumatic cognitions were assessed at pretreatment and Sessions 2, 4, 6, and 8. PTSD symptom severity and negative cognitions about the self and the world each decreased significantly from pre- to posttreatment, while self-blame cognitions were unchanged. Examination of temporal sequencing of changes during the course of PE via time-lagged mixed effects regression modeling revealed that preceding levels of negative cognitions about the world drove successive severity levels of PTSD symptoms, whereas preceding PTSD symptom severity did not drive subsequent negative cognitions about the world. Reductions in negative cognitions about the self led to subsequent improvement in PTSD. Improvement in PTSD symptoms in prior sessions was related to later reduction in negative cognitions about the self, though the impact of negative cognitions in influencing subsequent symptom change demonstrated a stronger effect. Results support that reductions in negative cognitions about the self and world are mechanisms of change in PE, which may have valuable implications for maximizing treatment effectiveness.