A Prospective 12-Year Study of Subsyndromal and Syndromal Depressive Symptoms in Unipolar Major Depressive Disorders

Abstract

LONGITUDINAL STUDIES of unipolar major depressive disorder (MDD) by Angst et al^1,2 and Keller et al^3-5 have described relapse and chronicity of major depressive episode (MDE) during the course of MDD. Detailed characterization of the disease between MDEs has rarely been the focus of systematic investigation. Some information on clinical course has been gleaned indirectly from cross-sectional studies of MDD in which alternative depressive subtypes have been described, eg, dysthymic disorder,⁶ minor depressive disorder (MinD),⁷ double depression,⁸ recurrent brief depression,⁹ and subsyndromal or subthreshold depressive symptoms (SSDs).^10-16