The stereotype of what it means to be bipolar--raging mood swings of uncontrollable mania alternating with weeks of immobilizing depression--represents just one type of bipolar disorder. The National Alliance for Research on Schizophrenia and Depression estimates that 5.7 million American adults suffer from this illness, but many of them go undiagnosed and untreated because they don't fit the classic mold.
All types of bipolar disorder share common characteristics. Sometimes referred to as manic-depressive illness, bipolar disorder affects the brain and causes unusual, severe shifts in a person's mood, energy, and activity levels.
Bipolar I Disorder
Bipolar I is the most severe of the four types of disorders. It involves manic episodes that last seven days or more, or manic symptoms that lead to hospitalization. The individual usually has depressive episodes as well, usually lasting at least two weeks and, without treatment, often lasting six to twelve months. The manic and depressive episodes alternate in a regular pattern. The symptoms cause significant negative effects on the individual's family, work and social life.
Bipolar II Disorder
Bipolar II is characterized by a pattern of primarily episodes of depression, alternating with hypomanic episodes lasting at least four days. Hypomania is similar to mania, but less severe and of shorter duration. However, these individuals suffer a more chronic course, with significantly more frequent depressive episodes and shorter periods of normal functioning between episodes than individuals with bipolar I. Individuals with bipolar II are at high risk for suicide.
Not Otherwise Specified
Bipolar disorder that does not appear to follow an apparent pattern and does not meet the criteria for type I or II is referred to as "not otherwise specified." For example, an individual whose symptoms do not last long enough to be classified as type I or II but whose symptoms are clearly out of his normal range of behavior would be considered to have bipolar disorder not otherwise specified.
Cyclothymia
Cyclothymia is the mildest form of bipolar disorder, involving episodes of hypomania alternating with mild depression over a period of at least two years. Hypomanic episodes with cyclothymia are characterized more by irritability than by euphoria, and single episodes may last as long as two months. Individuals with Cyclothymia may ultimately develop full-blown bipolar I or II disorder.
