Bipolar II Disorder
Unlike bipolar I disorder which is characterized by manic episodes, in bipolar II disorder, the patient suffers from one or more episodes of hypomania and one or more episodes of mild or major depression. As per the DSM-IV published by the American Psychiatric Association, hypomania differs from mania in the nature of severity of the symptoms. Hypomania is nothing but milder form of mania. But then, this makes the diagnosis of bipolar II disorder difficult as episodes of hypomania often go unnoticed and unreported.
Some of the common features of hypomania include decreased need for sleep, euphoria, increased levels of confidence, increased productivity at work, and increased tendency to take risk.