This is a randomized (study medication assigned to participants by chance), placebo- and positive-controlled, double-blind (Periods 1 to 3), and open-label (Period 4), single-dose, crossover study in up to 60 healthy adults. The study has a Screening Phase and a Treatment Phase. Participants will be randomly assigned to 1 of 6 treatment sequence groups and will receive the 4 treatments (1 treatment per period); Treatment A (intravenous placebo, Intranasal placebo and Oral placebo tablet matched to the moxifloxacin tablet), Treatment B (intravenous placebo, 84 milligram (mg) of intranasal esketamine as 4 devices, each with 28 mg esketamine and Oral placebo tablet matched to the moxifloxacin tablet), Treatment C (intravenous placebo, Intranasal placebo and 400 mg oral moxifloxacin tablet) and Treatment D (0.8 milligram per kilogram of intravenous esketamine, Intranasal placebo and Oral placebo tablet matched to the moxifloxacin tablet ). The first 3 periods will be double-blinded and the fourth period will be open-label. Periods 1, 2, 3, and 4 will be separated by 5 to 7 days. Primarily the effects of esketamine on QT/QTc intervals and electrocardiogram (ECG) morphology will be evaluated. Safety of the participants will be monitored throughout the study.
The purpose of the study is to assess the effects of esketamine on QT/QTc intervals and electrocardiogram (ECG) morphology at therapeutic exposures of esketamine and noresketamine (intranasal administration) and supratherapeutic exposures of esketamine (intravenous administration) in healthy adults.