Although the concept of a depressive personality has a long and rich tradition in psychiatry, it has only recently been included in any official nomenclature. Those afflicted with depressive personality have been subsumed under a variety of mood disorders and other personality disorders. This article presents criteria for depressive personality disorder that were developed for the DSM-IV Task Force. A framework for validating a personality disorder, including that of depressive personality disorder, is presented. Results of the DSM-IV Mood Disorders Field Trial relevant to this issue are reported in the article. Results show that DSM-IV depressive personality disorder identifies a group of patients whose diagnosis does not overlap substantially with major depression, dysthymia, or early-onset dysthymia; the patients have significant social and occupational morbidity. These results provide significant evidence to justify the validity of depressive personality disorder.