Bipolar I Disorder
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 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.
Bipolar II Disorder
Individuals with Bipolar II Disorder, unlike Bipolar I, have at least one current or past major depressive episode, with persistent depressed mood and/or loss of interest in most activities, and other characteristics of MDD (see description of MDD). Additionally, those with bipolar II disorder had experienced or are currently experiencing a hypomanic episode, that is, a period of elevated mood, typically accompanied by uncharacteristically high energy levels, minimal sleep, restlessness, fast speech, engagement in risky behaviors, and feelings of euphoria. Bipolar II may manifest with a cycle of intermittent major depression and hypomania, with depression often presenting more dominantly. Individuals with bipolar II disorder may not always fully identify the negative impact of the mood extremes on their daily lives.
Cyclothymic Disorder
Cyclothymic Disorder is characterized by an individual having periods of elevated mood (hypomanic symptoms) and periods of depressive symptoms for at least two years (one year for children and teenagers), with these highs and lows occurring during at least half that time. The fluctuations in mood are not sufficient in number, severity, or duration to meet the full criteria for a hypomanic or depressive episode, however they are present over fifty percent of the time. Individuals with cyclothymic disorder may be prone to labile mood, emotional dysregulation, and display an overreaction to minor stressors and disappointments. Symptoms of cyclothymic disorder include periods of stable moods usually lasting less than two months; cause distress or significant impairment in social or occupational functioning; cannot be accounted for by substance use or a medical condition; and do not meet the criteria for bipolar disorder, major depression or another mental disorder. Individuals with cyclothymic disorder are never symptom-free for more than two consecutive months.