Definition of Bipolar I disorder

Bipolar I disorder: Bipolar disorder in someone who has experienced depression and at least one episode of severe mania. Severe mania characteristically causes significant distress or greatly impairs one's work, family, or social life.

Bipolar I disorder is distinct from bipolar II disorder in which a person has had hypomania but not severe mania. Hypomanic episodes characteristically do not cause significant distress or greatly impair one's work, family, or social life.

See also: Bipolar disorder; Depression; Hypomania; Mania.