The co-occurrence of PTSD and dissociation: differentiating severe PTSD from dissociative-PTSD

Soc Psychiatry Psychiatr Epidemiol. 2014 Aug;49(8):1297-306. doi: 10.1007/s00127-014-0819-y. Epub 2014 Jan 21.


Purpose: A dissociative-posttraumatic stress disorder (PTSD) subtype has been included in the DSM-5. However, it is not yet clear whether certain socio-demographic characteristics or psychological/clinical constructs such as comorbid psychopathology differentiate between severe PTSD and dissociative-PTSD. The current study investigated the existence of a dissociative-PTSD subtype and explored whether a number of trauma and clinical covariates could differentiate between severe PTSD alone and dissociative-PTSD.

Methods: The current study utilized a sample of 432 treatment seeking Canadian military veterans. Participants were assessed with the Clinician Administered PTSD Scale (CAPS) and self-report measures of traumatic life events, depression, and anxiety. CAPS severity scores were created reflecting the sum of the frequency and intensity items from each of the 17 PTSD and 3 dissociation items. The CAPS severity scores were used as indicators in a latent profile analysis (LPA) to investigate the existence of a dissociative-PTSD subtype. Subsequently, several covariates were added to the model to explore differences between severe PTSD alone and dissociative-PTSD.

Results: The LPA identified five classes: one of which constituted a severe PTSD group (30.5 %), and one of which constituted a dissociative-PTSD group (13.7 %). None of the included, demographic, trauma, or clinical covariates were significantly predictive of membership in the dissociative-PTSD group compared to the severe PTSD group.

Conclusions: In conclusion, a significant proportion of individuals report high levels of dissociation alongside their PTSD, which constitutes a dissociative-PTSD subtype. Further investigation is needed to identify which factors may increase or decrease the likelihood of membership in a dissociative-PTSD subtype group compared to a severe PTSD only group.

MeSH terms

  • Adult
  • Canada / epidemiology
  • Comorbidity
  • Depression
  • Diagnostic and Statistical Manual of Mental Disorders
  • Dissociative Disorders / epidemiology*
  • Dissociative Disorders / psychology
  • Female
  • Humans
  • Male
  • Military Personnel / psychology*
  • Military Personnel / statistics & numerical data
  • Severity of Illness Index
  • Stress Disorders, Post-Traumatic / epidemiology*
  • Stress Disorders, Post-Traumatic / psychology
  • Veterans / psychology*
  • Veterans / statistics & numerical data