Overview

The purpose of this study to evaluate the efficacy of SAGE-217 in the treatment of participants with MDD.

Eligibility

Inclusion Criteria:

1. Participant with diagnosis of MDD as diagnosed by Structured Clinical Interview for Diagnostic and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) Clinical Trial Version [SCID-5-CT], with symptoms that have been present for at least a 4-week period.
2. Participant has a Hamilton Rating Scale for Depression (HAM-D) total score 24 at screening and Day 1 (prior to dosing).
3. Participants taking antidepressants must have been taking these medications at the same dose for at least 60 days prior to Day 1. Participants who have stopped taking antidepressants within 60 days must have stopped for longer than 5 half-lives of the antidepressant prior to Day 1. Participants receiving psychotherapy must have been receiving therapy on a regular schedule for at least 60 days prior to Day 1.
4. Participant is willing to delay start of other antidepressant or antianxiety medications and any new pharmacotherapy regimens, including as-needed benzodiazepine anxiolytics and sleep aids, until after completion of the Day 42 visit.

Exclusion Criteria:

1. Participant is currently at significant risk of suicide, as judged by the Investigator, or has attempted suicide associated with the current episode of MDD.
2. Participant has onset of the current depressive episode during pregnancy or 4 weeks postpartum, or the participant has presented for screening during the 6-month postpartum period.
3. Participant has a body mass index (BMI) 18 or 45 kg/m^2 at Screening, which is subject to a broader evaluation of medical comorbidities.
4. Participant has treatment-resistant depression, defined as persistent depressive symptoms despite treatment with adequate doses of antidepressants within the current major depressive episode (excluding antipsychotics) from two different classes for at least 4 weeks of treatment.
5. Participant has a medical history of seizures, bipolar disorder, schizophrenia, and/or schizoaffective disorder.
6. Participant has a history of mild, moderate, or severe substance use disorder (including benzodiazepines) diagnosed using DSM-5 criteria in the 12 months prior to screening.
7. Participant is taking psychostimulants (eg, methylphenidate, amphetamine) or opioids, regularly or as-needed, at Day -28.