*What is rapid cycling?*
Rapid cycling is a stage in bipolar disorder, not a different type of bipolar disorder.
It is defined as having four or more episodes (mania, hypomania, depression) in a 12 month period.
A person can have four or more episodes in many different ways. For example:
1. Four or more separate episodes, each with a two-month interval between each episode during which the person does not have to be 100% OK, but did not meet the diagnostic criteria for that type of episode (either depression, hypomania, or mania).
2. More commonly, four or more episodes that are considered different episodes because the person switched from one polarity to another. Mania to depression, depression to hypomania, etc. So, if a person switches from mania to depression or vice versa with either no interval at all or an interval less than 2 months–they are still two different episodes.
Why is it important to identify that the person has rapid cycling?
1. Greater prevalence of drug and alcohol abuse. If rapid cycling is present, the person should be reevaluated for possible substance abuse (by history, history from friends and family, and urine drug screen if needed).
2. Greater risk of suicidality, so rapid cycling should be taken very seriously.
3. Harder to treat. So, we should try to prevent rapid cycling if at all possible.
4. May affect the choice of medications.
5. Suggests that thyroid function should be checked because hypothyroidism predisposes to rapid cycling.
6. Suggests that if the person is on an antidepressant, it should be tapered off because antidepressants may cause and/or worsen rapid cycling.
So, evaluate every person with bipolar disorder for presence or absence of rapid cycling