RDC depressive subtypes: are they valid?

Ninety patients meeting the Research Diagnostic Criteria (RDC) for major depressive disorder were further diagnosed using the RDC depressive subtypes. Patients with specific RDC subtype diagnoses were compared to those who did not meet the subtype criteria on several variables, including family history, illness course, work history, social history, previous treatment, quality of remissions, and symptomatology. Several items significantly differentiated patients diagnosed as primary, psychotic, and situational from those not so diagnosed: this supports the validity of these subtype categories. However, the study did not support the validity of the incapacitated, agitated, and retarded subtypes. No conclusions could be drawn regarding the endogenous, simple, or recurrent unipolar depressive subtypes.