The purpose of this study is to compare the pharmacokinetics, safety, and tolerability of intranasally administered esketamine in elderly participants (greater than equal to [>=] 75 years of age) and younger healthy adult participants (18 to 55 years of age, inclusive).

This is a single-center, 2-cohort, single-dose, open-label study. The duration of study will be approximately 42 days per participant. The study consists of 3 parts: Screening (that is, 28 days before study commences on Day 1) and open-label Treatment (Day 1) and Follow-up (up to Day 13). Esketamine will be administered by intranasal route (delivery of medications through the nasal mucosa) on Day 1. Participants' safety will be monitored throughout the study.

Inclusion Criteria:

• For Cohort 1, be a man or woman, >= 75 years of age who are either healthy or who present with stable, well-controlled, chronic conditions which frequently occur in the elderly, such as: hyperlipidemia; controlled hypertension; impaired fasting glucose, impaired glucose tolerance or type 2 diabetes mellitus controlled with diet, and/or metformin monotherapy, dipeptidyl peptidase-4 (DPP-4) inhibitor monotherapy or a combination of metformin and DPP-4 inhibitor, who have glycated hemoglobin (HbA1c) levels less than 8 percent; degenerative joint disorders and osteoporosis; kidney function decline appropriate for age. Inclusion of participants with other chronic, well-controlled and stable conditions to Cohort 1 should be reviewed and agreed between the Investigator and the Sponsor
• For Cohort 2, be a man or woman, 18 to 55 years of age, inclusive
• For women of childbearing potential in Cohort 2, must have a negative serum beta-human chorionic gonadotropin (hCG) pregnancy test at screening; and a negative urine pregnancy test on Day -1
• If a man, must agree to use an adequate contraception method as deemed appropriate by the investigator and to not donate sperm during the study and for 3 months after receiving the study drug
• Body mass index (BMI) (weight [kg]/height^2 [m]^2) between 18 and 32 kg/m^2 (inclusive), and body weight not less than 50 kg

Exclusion Criteria:

• Diagnosed with a current or previous psychiatric disorder including but not limited to psychotic, bipolar, major depressive, or anxiety disorder
• Clinically significant medical illness
• Severe renal impairment
• Clinically significant abnormal values for hematology, clinical chemistry, or urinalysis at screening or at admission to the study center (Day -1) as deemed appropriate by the investigator
• History of drug or alcohol abuse disorder within the past 1 year, or a reason to believe a participant has such a history