According to the National Institute of Mental Health, there are three major types of bipolar disorder:

1. Bipolar I: Manic episodes that last at least 7 days, or by manic symptoms that are so severe that the person needs immediate hospital care. Usually, depressive episodes occur as well, typically lasting at least 2 weeks. Episodes of depression with mixed features (having depression and manic symptoms at the same time) are also possible.
2. Bipolar II: A pattern of depressive episodes and hypomanic episodes, but not the full-blown manic episodes described above.
3. Cyclothymia: Numerous periods of hypomanic symptoms as well numerous periods of depressive symptoms lasting for at least 2 years (1 year in children and adolescents). However, the symptoms do not meet the diagnostic requirements for a hypomanic episode and a depressive episode.

DSM-IV (ICD-10) Codes

Bipolar I: DSM-IV and ICD-10 codes are varied. Check the DSM-IV for the correct code.

Bipolar II: 296.89 (F31.81)

Cyclothymia: 301.13 (F34.0)

According to the National Institute of Mental Health,

• Bipolar disorder affects 2.6% of adults each year
• The average age of bipolar disorder onset is 25 years old
• Community studies suggest the prevalence of bipolar spectrum disorders to be 0-3%