A Randomized, Double-blind, Multicenter, Placebo-controlled Study to Evaluate the Efficacy, Safety, and Tolerability of Esketamine Nasal Spray, Administered as Monotherapy, in Adult Participants With Treatment-resistant Depression

The purpose of this study is to evaluate the efficacy of each individual dose of esketamine nasal spray, 56 milligram (mg) and 84 mg, compared with placebo nasal spray in improving depressive symptoms in participants with treatment resistant depression (TRD), as assessed by the change from baseline in the Montgomery-Asberg Depression Rating Scale (MADRS) total score from Day 1 (prerandomization) to the end of the 4 week double-blind treatment phase (Day 28).