AN MCMI CLUSTER TYPOLOGY OF OBSESSIVE COMPULSIVES - A MEASURE OF PERSONALITY-CHARACTERISTICS AND ITS RELATIONSHIP TO TREATMENT PARTICIPATION, COMPLIANCE AND OUTCOME IN BEHAVIOR-THERAPY

The two-fold purpose of this investigation was to (a) define personality subtypes among patients diagnosed with obsessive compulsive disorder (OCD) and (b) examine the relationship between the resulting typology and treatment participation, compliance and outcome of OCD patients treated with behavior therapy, using exposure and response prevention. A hierarchical agglomerative cluster analysis was performed on the Millon Clinical Multiaxial Inventory (MCMI) scale scores of 137 OCD patients seeking outpatient treatment; four cluster types emerged. Patients' OCD symptom severity was assessed at pretreatment, posttreatment, and 6-month follow-up using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Patients with no evident personality pathology and those with dependent qualities demonstrated the best overall outcome. Patients whose personalities indicated particular difficulties with interpersonal interaction were most likely to refuse behavior therapy and, among these patients who engaged in treatment, evidenced no reduction in OCD symptoms at posttreatment and follow-up. Patients with histrionic/borderline traits showed symptom reductions at posttreatment, but did not maintain their treatment gains at follow-up. The clinical implications of these findings are discussed.