A Study to Evaluate the Safety and Efficacy of Intranasal Esketamine in Treatment-resistant Depression

Inclusion Criteria:

--Participant must meet Diagnostic and Statistical Manual of Mental Disorders -Fourth Edition -Text Revised (DSM-IV-TR) diagnostic criteria for Major Depressive Disorder (MDD), without psychotic features, based upon clinical assessment, and confirmed by the Mini International Neuropsychiatric Interview (MINI)-Participant's major depressive episode and treatment response must be deemed "valid" by remote independent raters-Participant must have had an inadequate response to at least 2 antidepressants, at least one of which is in the current episode of depression; the antidepressant treatment response questionnaire (ATRQ) will be used to assess antidepressant treatment response during the current episode; prior medication history will be used to determine antidepressant treatment response in prior episode(s) -Have an Inventory of Depressive Symptoms-Clinician rated, 30-item (IDS-C30) total score \>=34 at Screening and predose at Day 1

Exclusion Criteria:

-Participant has a current DSM-IV-TR diagnosis of bipolar and related disorders, intellectual disability, or cluster b personality disorder (e.g., borderline personality disorder, antisocial personality disorder, histrionic personality disorder, and narcissistic personality disorder) -Participant has a current or prior DSM-IV-TR diagnosis of a psychotic disorder, MDD with psychosis, post-traumatic stress disorder (PTSD), or obsessive compulsive disorder (OCD) -Anatomical or medical conditions that may impede delivery or absorption of study medication (e.g., undergone facial reconstruction, rhinoplasty, significant structural or functional abnormalities of the nose or upper airway; obstructions or mucosal lesions of the nostrils or nasal passages; undergone sinus surgery in the previous 2 years; signs and symptoms of rhinitis) -Has an abnormal or deviated nasal septum with any 1 or more of the following symptoms: blockage of 1 or both nostrils, nasal congestion (especially 1-sided), frequent nosebleeds, frequent sinus infections, and at times has facial pain, headaches, and postnasal drip -Has a history of substance abuse (drug or alcohol) or dependence (except nicotine or caffeine) within the previous 1 year of the screening visit -Participant has known allergies, hypersensitivity, intolerance, or contraindication to esketamine/ketamine or its excipients