RecruitingPhase 3Drug trialA Study of Esketamine Nasal Spray Versus Placebo Spray in Adult Participants With Treatment-resistant DepressionThe purpose of this study is to evaluate how well each individual dose of esketamine (56 milligrams \[mg\] and 84 mg) works when compared with placebo in improving depressive symptoms in participants with treatment resistant depression (individuals with major depressive disorder \[MDD\] who have not responded to at least 2 different antidepressant treatments given at an adequate dose for an adequate duration in the current episode of depression).