Depressive personality disorder (DPD), which has a long tradition in psychiatry, currently resides in Appendix B (“Disorders for Further Study”) of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. After a brief outline of this history, the authors review empirical research on DPD using the Robins and Guze criteria (discussed later) for diagnostic and clinical validity as a framework. Although DPD has unique features, the authors argue that this diagnosis can largely be subsumed under dysthymic disorder. As a result of diagnostic confusion, and of the small amount of research conducted in this area, recommendations for the assessment and treatment of DPD are necessarily speculative. The authors conclude that if personality disorders are maintained as categoric constructs, DPD may best be understood as a subtype of dysthymic disorder. A more radical solution would be to conceptualize DPD, along with the other personality disorders, as extreme positions along dimensional continua.