The dissociative subtype of PTSD: a replication and extension

The nature of the relationship between dissociation and posttraumatic stress disorder (PTSD) has clinical and nosological importance. The aim of this study was to evaluate the evidence for a dissociative subtype of PTSD in two independent samples and to examine the pattern of personality disorder (PD) comorbidity associated with the dissociative subtype of PTSD.

Latent profile analyses were conducted on PTSD and dissociation items reflecting derealization and depersonalization in two samples of archived data: Study 1 included 360 male Vietnam War Veterans with combat-related PTSD; Study 2 included 284 female Veterans and active duty service personnel with PTSD and a high base rate of exposure to sexual trauma.

The latent profile analysis yielded evidence for a three-class solution in both samples: the model was defined by moderate and high PTSD classes and a class marked by high PTSD severity coupled with high levels of dissociation. Approximately 15% of the male sample and 30% of the female sample were classified into the dissociative class. Women (but not men) in the dissociative group exhibited higher levels of comorbid avoidant and borderline PD diagnoses.

Results provide support for a dissociative subtype of PTSD and also suggest that dissociation may play a role in the frequent co-occurrence of PTSD and borderline PD among women. These results are pertinent to the on-going revisions to the DSM and suggest that consideration should be given to incorporating a dissociative subtype into the revised PTSD criteria.