Patients with a DSM-IV-TR diagnosis of major depressive episode associated with bipolar I disorder , with or without rapid cycling , and with a Montgomery-Asberg Depression Rating Scale ( MADRS ) score 20 and a Young Mania Rating Scale ( YMRS ) score 12 were randomly assigned to 6 weeks of double-blind , once-daily treatment with lurasidone 20-60 mg , lurasidone 80-120 mg , or placebo .