Diagnosing personality disorders in the community. A comparison of self-report and interview measures.

The rapidly expanding empirical study of personality disorders is the result of the publication of operational diagnostic criteria in DSM-III and the development of instruments to assess these criteria. Few researchers have examined the comparability of measures of personality disorders, and to our knowledge there are no studies of the factors associated with discordance between measures. In the present study, 697 relatives of psychiatric patients and healthy controls were interviewed with the Structured Interview for Personality Disorders (SIDP) and completed the Personality Disorders Questionnaire (PDQ). Significantly more individuals had a personality disorder according to the SIDP; however, multiple personality disorders were more frequently diagnosed on the PDQ. Schizotypal, compulsive, dependent, and borderline personality disorders were significantly more frequently diagnosed by the PDQ, whereas the SIDP more frequently diagnosed antisocial and passive-aggressive personality disorder. The corresponding dimensional scores of the two measures were all significantly correlated; however, the concordance for categorical diagnoses was poor. Discrepancies between the PDQ and the SIPD dimensional scores were significantly associated with current level of depressive symptoms and PDQ lie scale scores.