A Long-Term Extension Study for Participants With Treatment-resistant Major Depressive Disorder Who Are Continuing Esketamine Nasal Spray Treatment

Inclusion Criteria: * Completed the maintenance phase (Week 32) of Study 54135419TRD3013 (NCT04338321) and had esketamine nasal spray in combination with continuing selective serotonin reuptake inhibitor/serotonin-norepinephrine reuptake inhibitor (SSRI/SNRI) administered through Week 30 (every 2 week dosing) or Week 31 (once weekly dosing) of Study 54135419TRD3013, and continues to be willing to be treated with esketamine nasal spray * Must, in the opinion of the investigator, be benefiting from continuation of esketamine nasal spray in combination with their current SSRI/SNRI based on efficacy and tolerability assessed on Day 1 of this study * Must be medically stable based on the investigator's judgment * A woman of childbearing potential must have a negative urine pregnancy test on Day 1 * Male participants who are sexually active with a woman of childbearing potential must agree to the following during the intervention period and for at least 1 spermatogenesis cycle (defined as approximately 90 days) after receiving the last dose of study intervention (that is, esketamine nasal spray), must fulfill the following criteria: must be practicing a highly effective method of contraception with his female partner, must use a condom if his partner is pregnant, and must agree not to donate sperm Exclusion Criteria: * Has any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant (example, compromise the well-being) or that could prevent, limit, or confound the protocol-specified assessments * Completed Study 54135419TRD3013 while presenting adverse events deemed clinically relevant by the investigator, and which may interfere with safety and well-being of the participant * Has developed during participation in Study 54135419TRD3013 any of the following cardiovascular-related conditions where an increase in blood pressure or intracranial pressure poses a serious risk: cerebrovascular disease following stroke or transient ischemic attack, aneurysmal vascular disease (including intracranial, thoracic, or abdominal aorta, or peripheral arterial vessels), intracerebral hemorrhage, coronary artery disease following myocardial infarction, unstable angina, or revascularization procedure (example, coronary angioplasty or bypass graft surgery), uncontrolled brady- or tachyarrhythmias that lead to hemodynamic instability, hemodynamically significant valvular heart disease such as mitral regurgitation, aortic stenosis, or aortic regurgitation or heart failure (New York Heart Association \[NYHA\] Class III-IV) of any etiology * Significant pulmonary insufficiency, including chronic obstructive pulmonary disease * Has homicidal ideation or intent, per the investigator's clinical judgment; or has suicidal ideation with some intent to act within 1 month prior to Day 1, per the investigator's clinical judgment; or based on the Columbia-suicide severity rating scale (C-SSRS) performed at Week 32 visit of Study 54135419TRD3013, corresponding to a response of "Yes" on Item 4 (active suicidal ideation with some intent to act, without specific plan) or Item 5 (active suicidal ideation with specific plan and intent) for suicidal ideation * Pregnant, or breast-feeding, or planning to become pregnant while enrolled in this study or within 90 days after the last dose of study intervention