We carried out a secondary analysis of a double-blind, placebo-controlled trial of desvenlafaxine for major depressive disorder (MDD) to explore the associations between depressive symptoms and subtypes, and functional outcomes, including work functioning. Employed outpatients with MDD were assigned randomly in a 2 : 1 ratio to receive desvenlafaxine 50 mg/day or placebo for 12 weeks. Analyses were carried out post-hoc with the intent-to-treat (ITT) sample (N=427) and a prospectively defined modified ITT sample (N=310), composed of patients with baseline 17-item Hamilton Rating Scale for Depression score of at least 20. Functional outcomes at week 12 included items and factors from the Montgomery-Åsberg Depression Rating Scale, Sheehan Disability Scale, and the Work Productivity and Activity Impairment questionnaire. In the modified ITT sample, but not in the ITT sample, desvenlafaxine-treated patients showed significantly greater improvement in several functional outcomes in the responder, nonanxious, and normal-energy patient subgroups. Improvement in the 17-item Hamilton Rating Scale for Depression total score at week 2 predicted change at week 12 in several functional outcomes. Functional improvement at 12 weeks was greater in subgroups of patients and was also significantly predicted by early improvement in depressive symptoms in employed patients with MDD treated with desvenlafaxine.
Trial registration: ClinicalTrials.gov NCT00824291.