A Clinical Study to Test the Effectiveness of an Investigational Drug to Treat People That Have Major Depressive Episodes When They Have Bipolar 1 Depression

Inclusion Criteria: * Subject is 18 to 65 years of age, inclusive, at the time of informed consent with bipolar I disorder, current episode depressed with or without rapid cycling disease course (≥ 4 episodes of mood disturbance but \< 8 episodes in the previous 12 months) with or without psychotic features (diagnosed by DSM 5 criteria, and confirmed by the SCID 5 CT). The current episode of major depression associated with bipolar I disorder must be confirmed by the Investigator and noted in the source records. * Subject provides written informed consent and is willing and able to comply with the protocol in the opinion of the investigator. * Subject or legally acceptable representative must possess an educational level and degree of understanding of English or the local language that enables them to communicate suitably with the Investigator and the study coordinator. * Subject must have a lifetime history of at least one bipolar manic or mixed manic episode. It is strongly recommended that a reliable informant (e.g., family member or caregiver) be available to confirm this history. * Subject's current major depressive episode is ≥ 4 weeks and less than 12 months in duration at Screening. * Subject has a MADRS total score ≥ 22 at both Screening and Baseline. * Subject has a YMRS total score ≤ 12 at Screening. * Female subjects of childbearing potential must have a negative serum ß-hCG test at Screening. * Females who participate in this study must be . one of the following…