Bipolar I disorder, also known as manic depression, is a mood disorder that affects 0.4 percent to 1.6 percent of the general population, and has been found to be equally common in both men and women. The course of bipolar I tends to be lifelong, although there are typically symptom-free periods. There are six subtypes of bipolar I disorder, each distinguished by the nature of the most recent mood episode. In each of the subtypes, there must have been one or more manic or mixed mood episodes.
Manic and Mixed Episodes
In order to be diagnosed with bipolar I disorder, an individual must have experienced one or more manic or mixed episodes in the course of their illness. A manic episode is a period of unusually elevated, excitable or irritable mood that lasts for at least one week. Along with elevated mood, three or more of the following symptoms need to be present: inflated self-esteem; decreased need for sleep; more talkative or pressured speech; racing thoughts; distractibility; increase in goal-directed behavior; increased physical movements; and increased participation in pleasurable activities that likely have negative consequences, such as excessive shopping. These symptoms must have a marked impact on a person's occupational or social functioning and cannot be accounted for by a substance or medical condition.
A mixed episode is diagnosed when a person experiences both a manic episode and a major depressive episode, rapidly alternating with one another. A major depressive episode includes the following symptoms, which have to last for at least two weeks: depressed mood, loss of interest or pleasure, change in weight or appetite, change in sleep pattern, increased restlessness, decreased physical activity, fatigue, feelings of worthlessness, difficulty concentrating or making decisions, and/or thoughts of death or suicide. As with a manic episode, a mixed episode must have a significant impact on a person's functioning and cannot be accounted for by a substance or a medical condition.
Single Manic Episode
In this subtype of bipolar I disorder, there must be only one manic episode with no previous major depressive episodes. The manic episode cannot be better accounted by another psychological disorder.
Most Recent Episode Hypomanic
For this subtype, the most recent or current episode must meet the criteria for a hypomanic episode. Hypomanic and manic episodes are very similar, except that a manic episode has a much more severe impact on a person's ability to function and may lead to hospitalization.
In addition to a most recent hypomanic episode, this subtype is also characterized by at least one manic or mixed episode.
Most Recent Episode Manic
The current or most recent mood episode must be a manic episode for this subtype, along with a previous history of at least one manic or mixed episode.
Most Recent Episode Mixed
In order to be diagnosed with this subtype, the most current or recent mood episode must be a mixed episode. Additionally, there must have been at least one major depressive episode, manic episode or mixed episode.
Most Recent Episode Depressed
The current or most recent episode must be a major depressive episode. Also, there must be a history of at least one manic or mixed episode.
Most Recent Episode Unspecified
For this subtype, an individual's most recent or current episode must meet all of the criteria for a manic, hypomanic, mixed or major depressive episode, except for duration of time. There must also be a history of at least one manic or mixed episode.
References
- Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; American Psychiatric Association; 2000
- National Institute of Mental Health: Bipolar Disorder
