Complexities in complex posttraumatic stress disorder in inpatient women: Evidence from cluster analysis of MCMI-III personality disorder scales

Herman's (1992a) clinical formulation of complex posttraumatic stress disorder (PTSD) captures the extensive diagnostic comorbidity seen in patients with a history of repeated interpersonal trauma and severe psychiatric disorders. Yet the sheer breadth of symptoms and personality disturbance encompassed by complex PTSD limits its descriptive usefulness. This study employed cluster analysis of the MCMI-111 (Millon, 1994) personality disorder scales to determine whether there is meaningful heterogeneity within a group of 227 severely traumatized women who were treated in a specialized inpatient program. The analysis distinguishes 5 clinically meaningful clusters, which we label alienated, withdrawn, aggressive, suffering, and adaptive. The study examined differences among these 5 personality disorder clusters on the MCMI-III clinical syndrome scales, as well as on the Brief Symptom Inventory (Derogatis, 1993), Dissociative Experiences Scale (E. M. Bernstein and Putnam, 1986), Adult Attachment Scale (Collins and Read, 1990), and Childhood Trauma Questionnaire (D. P. Bernstein, 1995). We present a classification-tree method for determining the cluster membership of new cases and discuss the implications of the findings for diagnostic assessment, treatment, and research.