Introduction to Bipolar Disorder

Classification of Bipolar Disorder

The hallmark symptoms of bipolar disorder are manic and depressive episodes that are experienced by the patients in varying degrees of intensity and frequency. There are four types of bipolar disorder:

Bipolar I

Bipolar I is characterized by at least one episode of mania and typically one or more episodes of major depression, although depression is not required for the diagnosis of Bipolar I. Hypomanic and mixed states can occur and there may be mood swings between episodes. This is considered by the American Psychiatric Association (APA)to be the most severe form of bipolar disorder. During a manic episode the patients may become delusional and suffer from hallucinations, a condition called Bipolar I with Psychotic Features.

Bipolar II

This type of bipolar disorder is characterized primarily by major depressive episodes with one or more episodes of hypomania but not full-blown mania. Bipolar II is associated with an elevated suicide risk.

Cyclothymic Disorder

The American Psychiatric Association (APA) defines cyclothymic disorder as numerous periods of hypomanic and depressive symptoms lasting for at least two years during which time neither meet the criteria for fully developed mania or depression. While this disorder may not be as severe as the other types, it is more persistent and relief from symptoms usually lasts no more than two months. This disorder may be a precursor to full-blown bipolar disorder or may continue as a low-grade chronic condition.

Bipolar Disorder Not Otherwise Specified

The APA characterizes this condition as involving the presence of manic symptoms but the criteria for bipolar I, bipolar II, or cyclothymic disorder are not met. Depressive symptoms may be present but are not required for diagnosis.

Rapid Cycling

Rapid cycling is a complicated phase of bipolar disorder in which episodes of mania and depression alternate at least 4 times a year and, in severe cases, can even progress to several cycles a day. This phase of bipolar disorder affects approximately 15% of individuals. There are two types of rapid cycling:

• Primary rapid cycling - rapid cycling in the absence of provoking factors

• Secondary cycling - rapid cycling associated with other causes, (e.g., substance abuse or hypothyroidism)

Risk factors associated with rapid cycling include:

• Female gender - women are more likely than men to experience rapid cycling
• History of prior use of antidepressants
• Hypothyroidism - underactive thyroid gland producing insufficient levels of thyroid hormone
• Older age