BackgroundVortioxetine has demonstrated dose-dependent efficacy in patients with major depressive disorder (MDD), with the greatest effect observed with vortioxetine 20 mg/day. This analysis further explored the clinical relevance of the more rapid and greater improvement in depressive symptoms observed with vortioxetine 20 mg/day vs 10 mg/day.MethodsAnalysis of pooled data from six short-term (8-week), randomized, placebo-controlled, fixed-dose studies of vortioxetine 20 mg/day in patients with MDD (N = 2620). Symptomatic response (≥50% decrease in Montgomery–Åsberg Depression Rating Scale [MADRS] total score), sustained symptomatic response, and remission (MADRS total score ≤10) were assessed by vortioxetine dosage (20 or 10 mg/day).ResultsAfter 8 weeks, 51.4% of patients receiving vortioxetine 20 mg/day had achieved symptomatic response vs 46.0% of those receiving vortioxetine 10 mg/day (P < .05). Significantly more patients achieved symptomatic response vs placebo from week 2 onwards for vortioxetine 20 mg/day and from week 6 onwards for vortioxetine 10 mg/day (both P ≤ .05). Sustained response was achieved from week 4 for 26.0% of patients receiving vortioxetine 20 mg/day vs 19.1% of those receiving vortioxetine 10 mg/day (P < .01), increasing to 36.0% and 29.8%, respectively, over the 8-week treatment period (P < .05). At week 8, 32.0% of patients receiving vortioxetine 20 mg/day were in remission vs 28.2% of those receiving vortioxetine 10 mg/day (P = .09). Rates of adverse events and treatment withdrawal were not increased during the week following vortioxetine dose up-titration to 20 mg/day.ConclusionVortioxetine 20 mg/day provides more rapid and more sustained symptomatic response than vortioxetine 10 mg/day in patients with MDD, without compromising tolerability.