Screening Phase: Patients who have been prescribed a mood stabilizer for > 4 weeks and are on a therapeutic dose will proceed directly to the Screening Visit. For situations in which the patient prefers to be taking a mood stabilizer or where the treating psychiatrist feels it is clinically necessary, a mood stabilizer (lithium, divalproex, carbamazepine, lamotrigine, olanzapine, quetiapine, risperidone, aripiprazole, ziprasidone or lurasidone) will be initiated (see Mood Stabilizer Initiation section below). For this set of patients who do begin a mood stabilizer, the Screening Phase may last up to 8 weeks. Otherwise, subjects who do not come in on a mood stabilizer will proceed directly to screening.