CONTEXT: Vortioxetine (Lu AA21004) is an antidepressant with a mechanism of 
action thought to be related to a combination of 2 pharmacologic actions: direct 
modulation of several receptors and inhibition of the serotonin transporter.
OBJECTIVE: To evaluate the efficacy of vortioxetine 10 and 20 mg once daily in 
outpatients with major depressive disorder.
DESIGN, SETTING, AND PARTICIPANTS: This 8-week, multicenter, randomized, 
double-blind, placebo-controlled, parallel-group study was conducted from July 
2010 to January 2012 among adults with a primary diagnosis of recurrent major 
depressive disorder (DSM-IV-TR).
INTERVENTION: Eligible subjects were randomized in 1:1:1 ratio to 1 of 3 
treatment arms: vortioxetine 10 mg, vortioxetine 20 mg, or placebo once daily 
for 8 weeks. Subjects who completed the 8-week trial entered a 2-week blinded 
discontinuation period to assess potential discontinuation symptoms.
MAIN OUTCOME MEASURE: The primary endpoint was the least squares mean change in 
Montgomery-Asberg Depression Rating Scale (MADRS) total score from baseline. Key 
secondary outcomes were analyzed in the following prespecified sequential order: 
MADRS response (≥ 50% decrease from baseline in total score), Clinical Global 
Impressions-Improvement score, change from baseline in MADRS total score in 
subjects with baseline Hamilton Anxiety Rating Scale score ≥ 20, MADRS remission 
(total score ≤ 10), and change from baseline in Sheehan Disability Scale total 
score (all at week 8).
RESULTS: A total of 462 subjects were randomized to placebo (n = 157), 
vortioxetine 10 mg (n = 155), and vortioxetine 20 mg (n = 150). Mean (SE) 
reductions from baseline in MADRS total score (week 8) were -10.77 (± 0.807), 
-12.96 (± 0.832), and -14.41 (± 0.845) for the placebo, vortioxetine 10 mg (P = 
.058 vs placebo), and vortioxetine 20 mg (P = .002 vs placebo) groups. MADRS 
response/remission was achieved in 28.4%/14.2%, 33.8%/21.4%, and 39.2%/22.3% of 
subjects, respectively, in the 3 groups. Only MADRS response for vortioxetine 20 
mg significantly separated from placebo (P = .044). Treatment was well 
tolerated, with the most frequently reported adverse events consisting of 
nausea, headache, diarrhea, and dizziness.
CONCLUSIONS: Vortioxetine 20 mg significantly reduced MADRS total score at 8 
weeks in this study population. Overall, vortioxetine was well tolerated in this 
study.
TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01163266.