Mania prevalence

Bipolar disorder is characterized by episodes of mania or hypomania, which include hyperactivity, decreased need for sleep, and a euphoric or irritable mood. Additionally, persons with bipolar disorder may have episodes of depression similar to those seen in major depressive disorder. The lifetime prevalence of severe bipolar disorder is about 1% and 3-5% if milder cases are included, afflicting men and women equally. Both bipolar disorder and major depressive disorder tend to be episodic, and in the periods of time between episodes, persons may experience few or no symptoms. The etiology of bipolar disorder is predominately genetic, with a 70% concordance in monozygotic twins. The neurobiology of bipolar disorder is less well understood, and few animal models have been developed. Treatment of bipolar disorder usually involves mood stabilizer medications, including lithium, and the anticonvulsants valproate and carbamazepine. At times, antidepressant and antipsychotic medications are also used. 

Beginning with Kraepelin s (1921) systematic classification of dysphoric mania, considerable attention has been paid to mixed states of bipolar disorder. Kraepelin s model was based on variable symptom patterns expressed in three areas, mood, thought, and motor activity. Once considered to be uncommon, current estimates suggest that the prevalence rate for dysphoric, or mixed mania, is approximately 30 percent (McElroy et al. 1992). Debate continues regarding the status of mixed mania as a distinct affective state versus a form, or stage, of typical mania. However, there is convincing evidence to support the opinion that mixed episodes can be more severe, chronic, and difficult to treat than pure manic or depressive episodes (Clothier,... 

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