Chronic Depression and Comorbid Personality Disorders: Response to Sertraline Versus Imipramine

Background: Chronic subtypes of depression appear to be associated with high rates of Axis II personality disorder comorbidity. Few studies, though, have systematically examined the clinical correlates of Axis II personality disorder comorbidity or its effect on treatment response or time to response.

Method: 635 patients diagnosed with DSM-III-R chronic major depression or "double depression" (dysthymia with concurrent major depression) were randomized to 12 weeks of double-blind treatment with either sertraline or imipramine between February 1993 and December 1994. Axis II diagnoses were made using the personality disorders version of the DSM-III-R Structured Clinical Interview. The effect of study treatment was measured utilizing the Hamilton Rating Scale for Depression and the Clinical Global Impressions scale.

Results: Forty-six percent of patients met criteria for at least 1 comorbid Axis II personality disorder, with cluster C diagnoses being the most frequent at 39%; 21% met criteria for at least 2 Axis II personality disorders. A cluster C diagnosis was associated with significantly higher rates of early-onset depression (before age 21; 47% vs. 32% for no cluster C; p = .005) and comorbid anxiety disorder (34% vs. 18% for no cluster C; p < .001). Overall, the presence of Axis II personality disorder comorbidity had minimal-to-no effect on the ability to achieve either an antidepressant response or remission and had inconsistent effects on time to response. The presence of Axis II personality disorder comorbidity did not appear to reduce functional and quality-of-life improvements among patients responding to acute treatment with sertraline or imipramine.

Conclusion: In this treatment sample, rates of Axis II personality disorder comorbidity were substantial in patients suffering from chronic forms of depression. Axis II personality disorder comorbidity did not appear to diminish symptomatic response to acute treatment or associated improvement in functioning and quality of life.