The bipolar classifications in this post are loosely paraphrased from the DSM-IV—Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition published by the American Psychiatric Association, research by the National Institute of Mental Health, and interviews with leading bipolar experts.

Bipolar I

This is the most severe type of bipolar disorder and the classic type. A diagnosis of Bipolar I requires at least one full-blown episode some time during a person’s life that doctors cannot attribute to another cause, such as a medication or substance . The manic episode must last at least one week, or be serious enough to require or cause functional impairment in some aspect of a person’s life (marriage, career, finances, etc.). Interestingly, a major depressive episode is not required to be diagnosed with this form of bipolar disorder, but it is almost always present and usually even much more common than the manic episodes.
Bipolar II

Most experts agree that there are versions of bipolar disorder that don’t produce full mania, yet respond very well to mood-stabilizing medications. People whose symptoms fit this category are often diagnosed with Bipolar II, sometimes called “soft” bipolar. According to Dr. Ghaemi, the primary difference between Bipolar I and Bipolar II is that the manic symptoms of the latter are not severe enough to cause functional impairment.

“With Bipolar II, the sufferer won’t become so grandiose that he or she loses his job,” says Dr. Ghaemi. “They will be much more active than normal, but they won’t have problems due to those activities.”

To be diagnosed with Bipolar II, a person must experience at least one major depressive episode that doctors can’t attribute to another cause and at least one episode of hypomania during his or her lifetime. People with Bipolar II never experience a full-blown manic episode. If they do, their diagnosis would likely be upgraded to Bipolar I. Again, usually there are many more depressive than hypomanic episodes.

Cyclothymic Disorder

Sometimes called “bipolar lite,” this diagnosis requires multiple depressive and hypomanic episodes not extreme enough to warrant a diagnosis of Bipolar I or II. In some cases, and mania occur simultaneously, resulting in a state of chronic irritability. A person’s symptoms must last for at least two years with no more than two months of stable mood during that time. Some people with Cyclothymic disorder go on to develop a full-blown mixed or depressive episode, which usually leads doctors to upgrade their diagnosis to Bipolar I or II. Usually these symptoms are so mild that persons with this condition do not seek treatment. This variety can be seen as the personality manifestation of bipolar disorder in some people. If symptoms are severe enough to cause problems, then Cyclothymia usually is not the diagnosis, but rather type I or type II Bipolar Disorder.

Bipolar NOS (Not Otherwise Specified)

This form of bipolar requires manic or depressive episodes that doctors can’t categorize as unipolar depression. The episodes also can’t fit into any of the other bipolar categories. The Bipolar NOS label often applies in the following circumstances:

* Rapid mood fluctuations intense enough to qualify as manic, hypomanic, or depressive, but that don’t meet the duration requirements for a Bipolar I, Bipolar II, or Cyclothymic disorder diagnosis
* Hypomania without depression
* Mania or Cyclothymic disorder that occurs simultaneously with schizophrenia, psychotic disorder NOS, or delusional disorder (a disorder characterized by psychoses, hallucinations, and delusional thinking)
* Chronic depression or dysthymia (long-term, low-level depression) accompanied by hypomanic episodes.

Dr. Ghaemi suggests that this category also be used for persons with recurrent severe depression (but no clear hypomania) who also experience manic or hypomanic periods only with antidepressant use, or who have members diagnosed with bipolar disorder.


Rapid-Cycling

Rapid-cycling isn’t a separate type of bipolar disorder; it is a descriptor of the course of bp. It is more common in women than in men. To qualify as rapid-cycling, a person must experience four or more episodes (depression, mania, hypomania, or mixed state) in a year. The episodes must be full-blown and, in the case of mania or mixed state, last at least one week or result in hospitalization. A depression must last at least two weeks and a person’s hypomania must last at least four days. This term does NOT mean that one’s moods fluctuate on a day by day, or hour by hour basis. Such short-term mood shifts are common in mania and mixed episodes, and are not themselves diagnostic of anything.

For more information:

National Alliance on Mental Illness – ()

Depression and Bipolar Support Alliance – ()

National Institute of Mental Health (NIMH)

Mental Health America – (MHA) formerly National Mental Health Association)

Substance Abuse & Mental Health Services Administration (SAMHSA)