LIFE EVENTS AND THE RESEARCH DIAGNOSTIC-CRITERIA ENDOGENOUS SUBTYPE -A CONFIRMATION OF THE DISTINCTION USING THE BEDFORD-COLLEGE METHODS

Background: Despite the advances in biological and psychosocial assess ment methods, reliable distinction between depressed patients with end ogenous presentations or melancholic symptom features and those with n onendogenous presentations has remained elusive. Methods: Ninety patie nts with histories of frequent unipolar episodes classified as endogen ous or nonendogenous by the Research Diagnostic Criteria were intervie wed with the Bedford College Life Events and Difficulties Schedule reg arding the 6 months before onset of their most recent episode of depre ssion. Results: Patients meeting the Research Diagnostic Criteria for definite endogenous subtype differed significantly from patients with nonendogenous features in terms of the proportion experiencing severe life stress in the 6 months before onset of their depressive episode ( P less than or equal to.04). Furthermore, survival analysis revealed a closer temporal association between severe event and depression onset among patients with nonendogenous features (P<.02). Conclusion: Even among patients with a history of multiple recurrences of depression, p sychological stress plays an important role in the timing of onset of episodes characterized by nonendogenous features.