Background. Empirical data on the impact of personality pathology on acute treatment outcome for depression are mixed, in part because of challenges posed by assessing trait-like personality patterns while patients are in an active mood episode. To our knowledge, no previous study has examined the effect of personality pathology on maintenance treatment outcome. By maintenance treatment we refer to long-term treatment provided to prevent depression recurrence among remitted patients.
Method. Structured Clinical Interviews for the DSM-III-R Personality Disorders (SCID-II) were obtained on a sample of 125 recurrently depressed women following sustained remission of the acute mood episode and prior to entering maintenance treatment. SCID-II interviews were then repeated following 1 and 2 years of maintenance interpersonal psychotherapy.
Results. At the pre-maintenance assessment, 21·6% of the sample met SCID-II personality disorder criteria. Co-morbid personality pathology was related to an earlier age of onset, more previous depressive episodes, and a greater need for adjunctive pharmacotherapy to achieve remission of the acute mood episode. Co-morbid personality pathology predicted both higher rates of depression recurrence and a shorter time to recurrence over the 2-year course of maintenance treatment. Notably, among those patients who remained depression-free, continuous levels of personality pathology steadily declined over the 2-year course of maintenance therapy.
Conclusions. Results highlight the need for early and effective intervention of both episodic mood disorder and inter-episode interpersonal dysfunction inherent to the personality disorders. Future maintenance treatment trials are needed to clarify the relationship between episodic mood disorder and personality function over time.