Background: Depression with fewer symptoms than required for a DSM-IV diagnosis of Major Depressive Disorder (MDD) has consistently been found to be associated with functional impairment. In this study, we aim to define clinically significant depression below the DSM-IV threshold for Major Depressive Disorder (MOD) by means of functional impairment.
Methods: Data used are from 2157 respondents of the Netherlands Study of Depression and Anxiety (NESDA). The Composite International Diagnostic Interview (CIDI) and the Inventory for Depressive Symptomatology-Self Report (IDS-SR(30)) were compared in their association with functional impairment as measured by the World Health Organization Disability Assessment Schedule II (WHODAS II). We used ANCOVA, adjusting for gender, age, education and somatic conditions, and ROC analyses.
Results: The IDS-SR(30) (p
Limitations: Suggested cut-offs seem reasonable on the basis of converging findings, but in lack of a golden standard they remain somewhat arbitrary. Furthermore, the design of the study is cross-sectional in nature, no causal inferences between depression and functional impairment can be made.
Conclusions: Although both instruments are associated with functional impairment, the IDS-SR(30) seems better suited than the CIDI to define subthreshold depression, with a cut-off in the mild IDS-SR(30) range. (C) 2009 Elsevier B.V. All rights reserved.