OBJECTIVE: The development of a new structured interview for depressive personality disorder is described. METHOD: A literature search yielded 32 traits associated with depressive personality; these traits were then used to develop the interview. Interrater reliability for the interview was tested in an initial group of 16 patients with longstanding depressive personality traits. Data from a second group of 67 subjects--54 with a possible clinical diagnosis of depressive personality and 13 normal volunteers--were used to examine the interview's psychometric properties and to modify its content. Factor analysis of the traits in the interview and modification of the instrument's structure was carried out on the basis of data from a third group of 526 subjects who were participating in a large epidemiologic study of mood disorders. RESULTS: The Diagnostic Interview for Depressive Personality, which emerged from this process, assess 30 personality traits that were shown to have satisfactory interrater reliability (kappa = 0.67), test-retest reliability (kappa = 0.41), and diagnostic reliability (kappa = 0.62). A cutoff score of 42 (from a total possible score of 60) on the interview offers a useful threshold for diagnosis. CONCLUSIONS: This interview provides a reliable method for assessing depressive personality traits and establishing the diagnosis of depressive personality disorder.