Types

There are four major types of bipolar disorder:

• Bipolar I Disorder – involves at least one manic episode and often more than one major depressive episode.  A major depressive episode may last anywhere from weeks or months.  In between episodes, a person may function normally.
• Bipolar II Disorder – involves at least one major depressive episode but with at least one hypomanic episode.  As with the first type, a person may function normally between episodes.
• Cyclothymic Disorder – a mild form of bipolar disorder.  It also involves bouts of depression and hypomania but in shorter periods of time, less severe symptoms, and without a regular pattern.

Bipolar Disorder Not Otherwise Specified – different people have different symptoms and manifestations of the disorder.  Sometimes, they do not fall into the other three categories and thus are classified under this type.