Prevalence and correlates of the proposed DSM-5 diagnosis of Chronic Depressive Disorder

Context: The draft proposal to add Chronic Depressive Disorder to DSM-5 will combine DSM-IV Dysthymic Disorder and Major Depressive Disorder, with chronic specifier, into a single diagnosis. Objective: The objective of this study is to estimate the prevalence and correlates of the proposed DSM-5 diagnosis of Chronic Depressive Disorder using unit record data from the 2007 Australian National Survey of Mental Health and Wellbeing. Design: Secondary analysis of a nationally representative household survey. Setting: Urban and rural census tracts. Participants: One individual between the ages of 16 and 85 years from 8841 households was interviewed for the survey. Main outcome measure: Lifetime prevalence estimates for chronic and non-chronic depression were determined using data from the World Health Organization's Composite International Diagnostic Interview, version 3.0 (WMH-CIDI 3.0). Results: Chronic depression of at least two years' duration had a lifetime prevalence of 4.6% (95% CI: 3.9-5.3%) and was found in 29.4% (95% CI: 25.6-33.3%) of individuals with a lifetime depressive disorder. Higher rates of psychiatric co-morbidity (OR = 1.42; 95% CI = 1.26-1.61), older age (OR = 1.04; 95% CI = 1.02-1.05), a younger age of onset (OR = 0.97; 95% CI = 0.95-0.98) and more frequent episodes of depression (OR = 1.75; 95% CI = 1.07-2.86) were found to be significant correlates of chronic depression. The first episode of depression for individuals with chronic depression often developed after the death of someone close (OR = 2.38; 95% CI 1.16-5.79). Conclusions: Chronic depression is highly prevalent among community-residing persons and has a set of correlates that discriminate it from non-chronic depression. The distinction between chronic and non-chronic depression proposed for DSM-5, in the form of Chronic Depressive Disorder, seems to be warranted. (C) 2012 Elsevier B.V. All rights reserved.