Bipolar (I) Disorder, once known as Manic Depression, involves one or more manic episodes and one or more depressive episodes. Manic episodes are periods of time with abnormally-heightened energy levels, thoughts, and mood. During a manic episode, an individual may feel euphoric, get little or no sleep, experience pressured or racing thoughts and speech, and may engage in self-destructive or impulsive behavior. Severe manic episodes may also include psychotic-type symptoms such as hallucinations and delusions. Episodes of mania and depression may alternate rapidly, may be separated by periods of normal experience, or may occur simultaneously in a mixed episode. Based on the level of severity of episodes and duration/chronicity, individuals may be diagnosed with other variations of Bipolar Disorder that fall in this category including Bipolar (II) Disorder, and Cyclothymic Disorder.