A Study to Assess Electrophysiology, Safety, Tolerability, and Pharmacokinetics of Multiple Doses of SAGE-718 Using Ketamine Challenge in Healthy Subjects

Inclusion Criteria: 1. Subject has a body weight ≥50 kg and body mass index (BMI) ≥18.0 and ≤30.0 kg/m2 at screening. 2. Subject is healthy with no history or evidence of clinically relevant medical disorders as determined by the Investigator. Exclusion Criteria: 1. Subject has any clinically significant abnormal value for hematology, clinical chemistry, or urinalysis at screening or admission. 2. Subject has a history or presence of a neurologic disease or condition, including but not limited to epilepsy, closed head trauma with clinically significant sequelae, or a prior seizure. 3. Subject has a positive screening test for alcohol or drugs of abuse (including marijuana) at screening or admission.