['major depression']
['sage-217', 'placebo']

        Inclusion Criteria:

          -  Participant has a diagnosis of Major Depressive Disorder that has been present for at
             least a 4-week period as diagnosed by Structured Clinical Interview for DSM-IV Axis I
             Disorders (SCID-I)

        Exclusion Criteria:

          -  Participant has a history of suicide attempt

          -  Participant has a history of treatment-resistant depression, defined as persistent
             depressive symptoms despite treatment with adequate doses of antidepressants from two
             different classes for an adequate amount of time

          -  Participant has active psychosis

          -  Participant has a medical history of seizures

          -  Participant has a medical history of bipolar disorder, schizophrenia, and/or
             schizoaffective disorder
      