Major depression and personality disorder.

The authors examined an interview and paper-and-pencil assessment of the DSM-III personality disorders (PDs) in depressed inpatients, and depressed relatives of psychiatric patients and never-ill controls who had a lifetime history of major depression. The rates of PDs according to the Structured Interview for DSM-III Personality Disorders (SIDP) were similar in the two groups, except for borderline PD which was more frequent in the inpatients. Of the individuals with a PD, the patients were more likely than the relatives to have two or more PDs, and the borderline and histrionic patients were more prototypic of these disorders than were the borderline and histrionic relatives. In contrast to the SIDP results, the rates of PDs according to the Personality Disorders Questionnaire (PDQ) were higher in the patient sample. These results thus extend the previously described high rates of PDs in depressed patients to a sample of individuals with a lifetime history of treated or untreated depression, and they suggest that interview assessments of personality may be less sensitive to the state effects of depression than are questionnaires.