Axis II Pathology in Outpatients with Dissociative Identity Disorder

Forty-two outpatients with dissociative identity disorder (DID) and 16 outpatients with dissociative disorder not otherwise specified (DDNOS) were administered the Millon Clinical Multiaxial Inventory-II (MCMI-II), the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), and the Dissociative Experiences Scale (DES). DID patients manifested severe personality pathology (BR > 84) on a mean of 4.0 MCMI-II scales: avoidant (76%), self-defeating (68%), borderline (53%), and passive-aggressive (45%). DDNOS cases had severe personality pathology on fewer MCMI-II scales (mean = 1.69): avoidant (50%) and self-defeating (31%). The DID and DDNOS groups differed in their scores on the DES (means = 54.9 vs. 25.9), the PK-PTSD scale of the MMPI-2 (means = 33.6 vs. 21.7), and in the incidence of severe borderline pathology (53% vs. 6%). These data on personality pathology in DID patients are virtually identical to those of seven previous studies of personality pathology in chronic PTSD patients (i.e., avoidant, self-defeating, borderline, and passive-aggressive). Such robust convergence of findings supports the construct validity of DID as a form of posttraumatic disorder and suggests that there is a quite predictable personologic core to the clinical picture of severely traumatized individuals.