Minimal clinically important change in the MADRS anhedonia factor score: A pooled analysis of open-label studies with vortioxetine in patients with major depressive disorder

Background: It is previously reported that the Montgomery-& Aring;sberg Depression Rating Scale (MADRS) anhedonia factor score is correlated with scales assessing function in patients with major depressive disorder (MDD). Methods: This was an analysis of a database including 5 long-term, extension studies of prior controlled trials, which evaluated the effects of open-label, maintenance treatment with vortioxetine (5-20 mg/day over 1-year) in adults with MDD. We assessed the association of changes in MADRS anhedonia factor scores with changes in the Clinical Global Impression of Severity (CGI-S), Sheehan Disability scale (SDS), and the SF-36. A minimal clinically important change (MCIC) for MADRS anhedonia factor scores was determined using the CGI-S as anchor. Results: In patients who had completed the prior controlled studies, MADRS anhedonia factor scores continued to improve over 1-year of maintenance treatment (mean +/- SE change from baseline of -6.2 +/- 0.2 at Month 12). Change in MADRS anhedonia factors score correlated with change in CGI-S (Week 4, r = 0.71), SDS (Week 24 r = 0.60) and SF-36 domains (Week 24 r = -0.19 to -0.61) scores. Using a 1 level improvement on CGI-S as anchor, the MCIC for MADRS anhedonia factor scores versus baseline were - 4.6 at Week 4, -5.5 at Week 24, and - 5.3 at Week 52. Limitations: Neither the MADRS scale, nor the primary studies, were specifically designed to assess anhedonia. Conclusions: These open-label data suggest that patients treated with vortioxetine continued to show clinically relevant improvements in their anhedonia over 1-year of maintenance therapy. Improvements in anhedonia correlated with improvements in measures of functioning and quality of life.