Types of Bipolar Disorder

There are several types of bipolar disorder; all involve episodes of depression and mania to a degree.

Bipolar disorder is a lifelong illness. Episodes of mania and depression eventually can occur again, if you don't get treatment. A small percentage of people will continue to have symptoms, even after getting treatment for their bipolar disorder. Here are the types of bipolar disorder:

Bipolar I disorder involves episodes of severe mood swings, from mania to depression.

Bipolar II disorder is a milder form, involving milder episodes of hypomania that alternate with depression.

Cyclothymic disorder describes even milder mood changes.

With mixed bipolar  disorder, there is both mania and depression at the same time. "The person feels grandiose, with racing thoughts, all this energy -- but is also irritable, angry, moody, feeling bad," says Michael Aronson, MD, a clinical psychiatrist and consultant for WebMD. "This can be a dangerous mix."

Rapid-cycling bipolar disorder is characterized by four or more mood episodes that occur within a 12-month period. Some people experience multiple episodes within a single week, or even within a single day. Rapid cycling tends to develop later in the course of illness. Women are more likely than men to have rapid cycling. A rapid-cycling pattern increases risk for severe depression and suicide attempts.

Antidepressants are thought to trigger and prolong rapid cycling in bipolar disorder. However, that theory is controversial and is still being studied.