The study proposes to enroll 20 participants with a bipolar disorder who are currently in an episode of major depression.Magnetic resonance imaging (MRI), recordings of brain electrical activity (EEG), and psychological testing to explore possible predictors of lurasidone treatment response will be conducted. Blood samples will be collected for a future study of blood protein predictors of response. After testing, participants will receive an open-label 8-week trial of lurasidone (Latuda™) at approved dosage levels. Participants who attain remission of their major depressive episode will be eligible for a six-month continuation phase to explore predictors of sustained response to continuation treatment. Data analyses will use statistical testing to explore potential biological predictors of lurasidone response. This will provide a framework for clarifying which patients are best suited to this treatment and begin to develop a model for precision treatment of this difficult-to-treat disorder.