Individuals with bipolar disorder classically have cycles of depression alternating with euphoric/irritable mood states (called mania ). Several disorders of mood in addition to the depressive disorders listed in Different Types Of Depression involve depression as well as manic or hypo-manic mood states:
- Bipolar I disorder
- Bipolar II disorder
- Cyclothymia
- Mood disorder not otherwise specified
A manic episode is defined as a period of euphoric and/or irritable mood that lasts at least 4 days; it is characterized by a decreased need for sleep, racing thoughts, the need to keep speaking, inflated self-esteem or grandiose thinking, and excess goal-directed activities. The same group of symptoms also defines a hypomanic episode, but the severity is judged to be less. Individuals in the midst of a manic episode can become psychotic and require hospitalization.
In bipolar I disorder the person must have a history of at least one manic episode. The number of depressive episodes can be as few as none to any amount. Classically, an afflicted person alternates between episodes with normal mood in between. However, cycles can consist of any frequency of mood states in any order. Bipolar II disorder comprises depressive episodes alternating with hypomanic episodes only (no mania).
In cyclothymia no major depressive episode has occurred, but mild depressive episodes alternate with hypomanic states. Mood disorder not otherwise specified is also a condition of exclusion in that a mood disorder is considered present, but the criteria have not been met for the other conditions in the DSM-IV-TR . In someone presenting with depression, these conditions can only be excluded by a thorough history of symptoms and episodes in the past. Sometimes the patient does not recall such episodes, however, such that a bipolar condition is not learned of until the treatment for depression is initiated.