Study Evaluating DVS-233 SR In Adult Outpatients With Major Depressive Disorder

Primary Objective: To compare the efficacy and safety of DVS-233 SR versus placebo treatment in reducing the relapse rate of depressive symptoms in subjects with major depressive disorder (MDD), and to compare the percentages of relapse in terms of time to relapse between DVS-233 SR and placebo treatment groups by using survival analysis. Secondary Objective: To assess the response of subjects on DVS-233 SR versus placebo for the clinical global evaluation, functionality, general well-being, pain, and absence of symptoms (Hamilton Psychiatric Rating Scale for Depression, 17-item \[HAM-D17\] \< 7).