In DSM-III, this category is called Atypical Bipolar Disorder
This is a residual category for individuals with manic features that cannot be classified as Bipolar Disorder or as Cyclothymic Disorder. For example, an individual who previously had a major depressive episode and now has an episode of illness with some manic features (hypomanic episode), but not of sufficient severity and duration to meet the criteria for a manic episode. Such cases have been referred to as "Bipolar II."
In DSM-IV, this category is called Bipolar Disorder Not Otherwise Specified
The Bipolar Disorder Not Otherwise Specified category includes disorders with bipolar features that do not meet criteria for any specific Bipolar Disorder. Examples include
- Very rapid alternation (over days) between manic symptoms and depressive symptoms that do not meet minimal duration criteria for a Manic Episode or a Major Depressive Episode
- Recurrent Hypomanic Episodes without intercurrent depressive symptoms
- A Manic or Mixed Episode superimposed on Delusional Disorder, residual Schizophrenia, or Psychotic Disorder Not Otherwise Specified
- Situations in which the clinician has concluded that a Bipolar Disorder is present but is unable to determine whether it is primary, due to a general medical condition, or substance induced
This category applies to presentation in which symptoms characteristic of a bipolar and related disorder that cause clinically significant distress or impairment in social, occupational, or other important areas of functioning predominate but do not meet the full criteria for any of the disorders in the bipolar and related disorders diagnostic class. The unspecified bipolar and related disorder category is used in situations in which the clinician chooses not to specify the read that the criteria are not met for a specific bipolar and related disorder, and includes presentation in which there is insufficient information to make a more specific diagnosis (e.g., in emergency room settings).