Time to recovery of an inception cohort with hitherto untreated unipolar major depressive episodes

Abstract

Background: Generalisability of existing studies on the naturalistic history of major depression is undermined by overrepresentation of in-patients and tertiary care academic centres, inclusion of patients already on treatment and/or incomplete follow-up. Aims: To report the time to recovery of an inception cohort of unipolar major depressive episodes. Method: A multi-centre prospective follow-up study of patients with a mood disorder, who had been selected to be representative of the untreated first-visit patients at 23 psychiatric settings from all over Japan. Results: The median time to recovery of the index episode after treatment commencement was 3 months (95% Cl 2.5-3.6): 26% of the cohort reached asymptomatic or minimally symptomatic status by 1 month, 63% by 3 months, 85% by 12 months and 88% by 24 months. Conclusions: Our estimate of the episode length was 25-50% shorter than estimates reported in the literature. Declaration of interest: No conflict of interest. Funding from the Ministry of Health and Welfare, Japan.