A 2-Part Study (Open-label Followed by Double-blind, Randomized, Placebo-controlled, Parallel Group) of the Safety, Tolerability, Pharmacokinetics, and Efficacy of SAGE-217 in the Treatment of Subjects With Bipolar I/II Disorder With a Current Major Depressive Episode

Part A: Number of Participants With at Least One Treatment-Emergent Adverse Events (TEAEs)

Time Frame: From first dose of study drug up to Day 42

An adverse event (AE) was any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not related to the medicinal (investigational) product. A TEAE was defined as an adverse event with onset after the start of study through Day 42/early termination.

Part A: Number of Participants With TEAEs, Graded by Severity

Time Frame: From first dose of study drug up to Day 42

An adverse event (AE) was any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not related to the medicinal (investigational) product. A TEAE was defined as an adverse event with onset after the start of study through Day 42/early termination. Severity was assessed according to the following scale: mild (awareness of sign or symptom, but easily tolerated); moderate (discomfort sufficient to cause interference with normal activities); severe (incapacitating, with inability to perform normal activities).

Part A: Percentages of Participants With Response to Suicidal Ideation and Suicidal Behavior Based on the Columbia-Suicide Severity Rating Scale (C-SSRS)

Time Frame: Baseline, Post-baseline (any time up to Day 42)

Suicidality was monitored using the C-SSRS. This scale consists of a baseline evaluation that assesses the lifetime experience of the participant with suicidal ideation and behavior, and a post-baseline evaluation that focuses on suicidality since the last study visit. The C-SSRS includes 'yes' or 'no' responses for assessment of suicidal ideation (wish to be dead, non-specific active suicidal thoughts, active suicidal ideation with any methods, active suicidal ideation with some intent, active suicidal ideation with specific plan) and behavior (preparatory acts or behavior, aborted attempt, interrupted attempt, actual attempt (non-fatal), completed suicide). Percentage of participants with response 'yes' are reported for both suicidal ideation and behavior.

Part A: Change From Baseline in the Young Mania Rating Scale (YMRS) Total Score

Time Frame: Baseline, Days 3, 8, 12, 15, 21, 28, 35, and 42, Last value on treatment (up to Day 14), Last value on study (up to Day 42)

Manic symptoms were assessed during the study using the YMRS. The clinician-administered scale is based on 11 items of core symptoms of mania. Four of the items (irritability, speech, thought content, and disruptive/aggressive behavior) were graded on a scale of 0 to 8 (choices given as even numbers), with the remaining 7 items graded on a scale of 0 to 4. Scoring between the points given (whole or half points) is possible. The YMRS total score ranges from 0 (no symptoms) to 60 (extreme severity of symptoms). A higher total score indicates a greater degree of mania. A negative change indicates better state of health.

Part B: Change From Baseline in the 17-Item Hamilton Depression Rating Scale (HAM-D) Total Score

Time Frame: Baseline up to Day 42

The 17-item HAM-D was used to rate the severity of depression in participants who were identified as experiencing a major depressive episode (MDE). Items scored in a range of 0 to 2 include: insomnia (early, middle, late), somatic symptoms (gastrointestinal and general), genital symptoms, loss of weight, and insight. Items scored in a range of 0 to 4 include: agitation, depressed mood (sadness, hopeless, helpless, worthless), feelings of guilt, suicide, work and activities, retardation (slowness of thought and speech; impaired ability to concentrate; decreased motor activity), anxiety (psychic and somatic), hypochondriasis. The HAM-D total score was calculated as the sum of the 17 individual item scores, with a range of 0 (not at all depressed) to 52 (severely depressed). Higher scores indicated more depression. A negative change from baseline indicates improvement.