Assessing the relationship between functional impairment/recovery and depression severity: a pooled analysis.

The objective of this study was to explore the relationship between assessments of functional impairment, emotional well-being, and depression symptoms. Data were pooled from 3530 outpatients with major depressive disorder enrolled in 10 desvenlafaxine clinical trials. The primary outcome measures included (a) the 17-item Hamilton Rating Scale for Depression (HAM-D17) as a measure of depressive symptom severity and (b) the Sheehan Disability Scale (SDS) and five-item World Health Organization Well-Being Index (WHO-5) as measures of functional impairment and well-being. A linear regression model was used to identify the SDS and WHO-5 values that equate to the predetermined clinically relevant three-point difference between active treatment and placebo on the HAM-D17. A receiver operating characteristic analysis was conducted to determine the SDS score that equates to a remission of depression symptoms (i.e. HAM-D17≤7). An approximate three-point difference between active treatment and placebo on the SDS (2.8) and WHO-5 (2.5) was determined to be clinically relevant in relation to improvements in depressive symptoms. An SDS of less than or equal to 7 was equivalent to a remission of depression symptoms, providing a definition of functional remission. A better understanding of the relationship between depressive symptoms and functional impairment and well-being may provide clinicians with a more comprehensive means of assessing treatment effects in major depressive disorder.