A Study of Ketamine in Patients With Treatment-resistant Depression

Inclusion Criteria:

* Be medically stable on the basis of clinical laboratory tests performed at screening
* Meet diagnostic criteria for recurrent major depressive disorder (MDD), without psychotic features
* Have a history of inadequate response, ie treatment was not successful, to at least 1 antidepressant
* Have an Inventory of Depressive Symptoms-Clinician rated, 30 item (IDS-C30) total score \>= 40 at screening and predose at Day 1
* Inpatient or agreed to be admitted to the clinic on each dosing day

Exclusion Criteria:

* Has uncontrolled hypertension
* Has a history of, or current signs and symptoms of diseases, infections or conditions that in the opinion of the investigator, would make participation not be in the best interest (eg, compromise the well-being) of the patient or that could prevent, limit, or confound the protocol-specified assessments
* Has known allergies, hypersensitivity, or intolerance to ketamine or its excipients
* Is unable to read and understand the consent forms and patient reported outcomes, complete study-related procedures, and/or communicate with the study staff