Posttraumatic stress disorder (PTSD) criteria in DSM-5 included a dissociative diagnostic subtype characterized by a depersonalization item and a derealization item. Researchers have queried whether this was too restrictive, as alternative dissociative symptomatology may also be characteristic of the subtype. The current study utilized data from 318 Northern Irish students, of which 165 were trauma exposed. Participants were assessed for PTSD symptomatology based on DSM-5 criteria via a modified version of the PTSD Symptom Scale-Self-Report (PSS-5) and dissociative experiences via the Dissociative Experiences Scale (DES). Confirmatory factor analysis of PTSD and DES models revealed an optimal four-factor DSM-5 PTSD model including reexperiencing, avoidance, negative alterations in mood and cognitions, and alterations in hyperarousal and reactivity factors, and an optimal three-factor DES model including absorption, amnesia, and depersonalization/derealization factors. When comparing the correlations between depersonalization/derealization and the four PTSD factors, significant Wald tests of parameter constraints revealed that depersonalization/derealization is more related to alterations in arousal and reactivity (r = .432) compared to avoidance (r = .289), χ 2 (1, N = 165) = 8.352, p = .004. We discuss whether the mechanism for comorbid PTSD and dissociation may be related to PTSD's arousal factor.
- Confirmatory factor analysis
- Dissociative Experiences Scale
- Posttraumatic stress disorder