The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), defines three types of bipolar disorders (BDs). Bipolar I disorder (BD-I) is diagnosed on the basis of the occurrence of manic episodes: experiences of elevated, expansive, or irritable mood (known as mania) that result in distress or impaired functioning. Major depressive episodes, diagnosed on the experiences of clinically significant depressed mood, occur in the vast majority of BD-I cases, although they are not required for diagnosis in the DSM-5. Bipolar II disorder (BD-II) is diagnosed based on the occurrence of both major depressive episodes and hypomanic episodes and experiences of elevated, expansive, or irritable mood that are not severe enough to cause distress or impaired functioning. Cyclothymic disorder is diagnosed based on the occurrence ...