Longitudinal Change in Self-Reported Peritraumatic Dissociation During and After a Course of Posttraumatic Stress Disorder Treatment: Contributions of Symptom Severity and Time

Objective: Peritraumatic dissociation, a dissociative reaction that occurs at the time of a traumatic event, has been established as a strong risk factor for posttraumatic stress disorder (PTSD). However, self-reported peritraumatic dissociation is typically assessed months or years after trauma exposure and may be influenced by current distress levels and other factors. Method: We examined the temporal stability of scores on the Peritraumatic Dissociative Experiences Questionnaire (PDEQ) among 126 treatment-seeking adults with PTSD during and after trauma-focused treatment. Participants reported dissociation during the same index event at baseline and 6, 12, 24, 36, and 60 weeks after the first treatment session. Results: There were substantial changes in PDEQ total scores over time, with >40% of participants experiencing reliable change from baseline at least once during the study. Multilevel modeling revealed an overall decrease in PDEQ scores over time; scores on the Clinician-Administered PTSD Scale for DSM-5, Beck Depression Inventory-II, and PTSD Checklist for DSM-5 were each significantly associated with PDEQ scores. Conclusions: Our findings suggest the PDEQ does not provide temporally stable assessment of peritraumatic dissociation. Accordingly, it is crucial to control for current PTSD symptom levels when examining the degree to which peritraumatic dissociation confers risk for future symptom severity. Without such an accounting, our understanding of the relationship between PTSD and peritraumatic dissociation may be incorrect.