Rapid cycling is a pattern of frequent, distinct episodes in bipolar disorder. In rapid cycling, a person with the disorder experiences four or more episodes of mania or depression in one year. It can occur at any point in the course of bipolar disorder, and can come and go over many years depending on how well the illness is treated; it is not necessarily a "permanent" or indefinite pattern of episodes.
Virtually anyone can develop bipolar disorder. About 2.5% of the U.S. population suffers from some form of bipolar disorder – nearly 6 million people. A rapid cycling pattern may occur in about 10% to 20% of people with the disorder. Women, and people with bipolar II disorder, are more likely to experience periods of rapid cycling.
Most people are in their late teens or early 20s when symptoms of bipolar disorder first start. Nearly everyone with bipolar disorder develops it before age 50. People with an immediate family member with bipolar disorder are at higher risk.
What Are the Markers of Bipolar Disorder?
The major markers of bipolar disorder include:
At least 1 episode of mania in the patient's lifetime
Episodes of depression (major depressive disorder), which are often recurrent
Mania is a period of abnormally elevated mood and high energy, usually accompanied by erratic behavior lasting at least seven days at a time. Hypomania is an elevated mood not reaching full-blown mania a minimum of four days.
A few people with rapid cycling bipolar disorder alternate between periods of hypomania and major depressive disorder. Far more commonly, though, repeated and distinct episodes of depression dominate the picture. Repeated periods of depression are punctuated by infrequent, shorter periods of elevated or normal mood.
How Is Rapid Cycling Bipolar Disorder Identified?
Bipolar disorder is diagnosed after someone experiences a hypomanic or manic episode along with multiple additional episodes of either mania, hypomania or depression. Rapid cycling in itself is not a diagnosis, but rather a "course specifier" or descriptor of the course of illness. In bipolar disorder rapid cycling is identified when four or more distinct episodes of depression, mania, or hypomania occur during a one year period. Rapid cycling can occur at any time in the course of bipolar disorder and may come and go at varying points over a lifetime.
Rapid cycling bipolar disorder can be difficult to identify since some episodes can simply wax and wane without resolving. As a result, they don't necessarily represent multiple separate and distinct episodes. Rapid cycling may seem to make the changing mood states of bipolar disorder more obvious, but because most people with rapid cycling bipolar disorder spend far more time depressed than manic or hypomanic, they are often misdiagnosed with unipolar depression.
For example, in one study of people with bipolar II disorder, the amount of time spent depressed was more than 35 times the amount of time spent hypomanic. Also, people often don't take note of their own hypomanic symptoms, mistaking them for a period of unusually good mood.