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 disor der (PTSD) captures the extensive diagnostic comorbidity seen in patients w ith a history of repeated interpersonal trauma and severe psychiatric disor ders. Yet the sheer breadth of symptoms and personality disturbance encompa ssed by complex PTSD limits its descriptive usefulness. This study employed cluster analysis of the MCMI-III(Millon, 1994) personality disorder scales to determine whether there is meaningful heterogeneity within a group of 2 27 severely traumatized women who were treated in a specialized inpatient p rogram. The analysis distinguishes 5 clinically meaningful clusters, which we label alienated, withdrawn, aggressive, suffering, and adaptive. The stu dy examined differences among these 5 personality disorder clusters on the MCMI-III clinical syndrome scales, as well as on the Brief Symptom Inventor y (Derogatis, 1993) Dissociative Experiences Scale (E. M. Bernstein & Putna m, 1986), Adult Attachment Scale (Collins & Read, 1990), and Childhood Trau ma 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 rese arch.