Bipolar disorder is a mental condition marked by episodes of abnormally elevated or irritable mood. The symptoms must continue for at least a week. Physicians make a diagnosis of bipolar disorder if they determine that a person has had a past or current mood episode. Such an episode is a disturbance of mood accompanied by other ongoing symptoms and causing significant distress, disability, or both. A person with bipolar disorder typically has periods of normal mood that vary in length depending on the severity of the disorder.
Physicians recognize four primary types of mood episodes: (1) manic, (2) hypomanic, (3) depressive, and (4) mixed. A manic episode is a period of abnormally euphoric, elated, or irritable mood accompanied by other symptoms. These symptoms include rapid, often disorganized thinking; rapid and ceaseless speech; impulsive, reckless, or risky behavior; sleeplessness; and grandiosity (an exaggerated sense of self-importance). Hypomania is a less severe form of manic episode. A depressive episode typically involves sadness and loss of interest. Other symptoms include appetite and sleep disturbances, fatigue, difficulty concentrating, low self-worth or guilt, and suicidal thoughts or actions. A mixed episode combines symptoms of mania and depression.
Mental health experts recognize three primary types of bipolar disorders: (1) bipolar I, (2) bipolar II, and (3) cyclothymia. Bipolar I is defined by at least one manic or mixed episode. People with bipolar I also experience occasional episodes of depression. Bipolar II disorder involves hypomanic and depressive episodes without manic or mixed episodes. Cyclothymia is a chronic (ongoing) mood disturbance in which low-level depression and hypomania occur over years.
