This study examined the construct validity of depressive personality disorder (DPD: American Psychiatric Association, 1994). Adult psychiatric outpatients (N = 900) underwent comprehensive Axis I and II evaluations and provided data on 4,768 of their 1st-degree relatives. Despite modest overlap, DPD was not redundant with any Axis I or II disorder. Participants with DPD exhibited more Axis I and Axis II comorbidity, and greater psychosocial dysfunction, than participants without DPD. Relatives of participants with DPD had higher rates of mood disorders, alcohol abuse, and antisocial personality. Results are consistent with findings of several other similar investigations. The authors argue that DPD is a valid construct and should be conceptualized as a personality disorder as opposed to a mood disorder.