Bipolar Disorder is a group of brain disorders that cause extreme fluctuation in a person’s mood, energy, and ability to function. It includes three different conditions: bipolar I, bipolar II, and cyclothymic disorder. Bipolar I disorder is a manic-depressive disorder that can exist both with and without psychotic episodes. Bipolar II disorder consists of depressive and manic episodes which alternate and are typically less severe and do not inhibit function. Cyclothymic disorder is a cyclic disorder that causes brief episodes of hypomania and depression.