Depressive personality disorder: rates of comorbidity with personality disorders and relations to the five-factor model of personality.

Depressive personality disorder (DPD) is listed in the DSM-IV as one of the "Disorders for Further Study." In this investigation we examined (1) the rates of comorbidity of DPD with the 10 personality disorders (PDs) in the main text of DSM-IV, and (2) the convergent and discriminant validity of DPD in its relation to the 30 facet traits of the Five-Factor Model of personality (FFM). One hundred and sixty-nine participants with psychiatric diagnoses were interviewed with the Structured Clinical Interview for DSM-IV Personality Disorders Questionnaire (SCID-II) and completed the Revised NEO Personality Inventory (NEO PI-R). A total of 26 (15%) of the participants met diagnostic criteria for at least one of the 10 main text PDs, and 15 (9%) met criteria for DPD. Of those who met criteria for DPD, 10 (59%) of the participants also met criteria for one or more of the 10 main text PDs. Regression analyses indicated a four-facet trait set derived from the NEO PI-R thought to be uniquely associated with DPD accounted for a significant amount of variance in DPD SCID-II PD scores and was significantly larger for DPD than it was for the 9 of the 10 main text PDs; the sole exception was for avoidant PD. Diagnostically, DPD overlaps significantly with other PDs but is distinguishable in its unique relation with traits from the FFM.