Bipolar disorder or bipolar affective disorder is a psychiatric diagnosis that classifies a category of mood disorders by the presence of one or more episodes of unusually high energy levels with or without one or more depressed episodes. These episodes are usually separated by times of “normal” mood; but, with some individuals, depression and mania may quickly alternate, which is known as rapid cycling. The disorder has been subdivided into bipolar I, bipolar II, cyclothymia, and other types, based on the severity and nature of mood episodes experienced. Symptoms usually appear in late adolescence or young adulthood. The diagnosis of Bipolar disorder is based on the evaluation of a person’s self-reported experiences, as well as observed behavior.