An investigation of the effects of comorbid Axis II pathology on outcome of inpatient treatment for unipolar depression

DSM-based research on comorbidity has suggested that depression and personality disorder frequently occur together and that the combination of syndromes is associated with a poor response to treatment for depression. The present study was designed to explore the effect of comorbid Axis II pathology for a sample of 45 inpatients who received treatment for major depression. Both categorical and dimensional ratings of personality disorder were used in the statistical analysis. Positive categorical diagnosis of Cluster C (anxious-avoidant) disorder as well as higher dimensional rating of Cluster A (odd-eccentric) pathology, was predictive of a poor response to treatment (p <.05), as measured by change in pre-post clinical ratings on the Montgomery-Asberg Depression Rating Scale. These results were construed as indicative of a significant Axis II comorbidity effect in the context of an inpatient, multimodal treatment setting for depression. The results also spotlight the influence of techniques of measurement in determining the outcome of statistical analysis.