Effects of axis I and II comorbidity on behavior therapy outcome for obsessive-compulsive disorder and agoraphobia

The impact of concurrent axis I diagnoses and axis II traits on the efficacy of a 22-session exposure-based treatment program for 43 outpatients with panic disorder and agoraphobia (PDA) and 63 with obsessive-compulsive disorder (OCD) was examined. Trained interviewers used the Structured Clinical Interview for DSM-III-R (SCID) to assess axis I diagnoses and the SCID-II to identify the number of axis II criteria met for anxious, dramatic, and odd clusters. Among axis I diagnoses, secondary major depressive disorder (MDD), dysthymia, social phobia, and generalized anxiety disorder (GAD) were present in sufficient numbers to study their effects on treatment outcome. Outcomes were assessed on self-rated target fears and functioning and on a behavioral avoidance test at post-treatment and at 6 months follow-up. Only GAD comorbidity predicted dropout, whereas MDD and all three personality cluster traits predicted post-treatment outcomes. Follow-up analyses showed significant effects of MDD and GAD, but axis II cluster criteria were not predictive.