Bipolar Disorder

Bipolar disorder, formerly known as manic-depressive illness, is a brain and behavior disorder characterized by severe shifts in a person's mood and energy, making it difficult for the person to function. More than 5.7 million American adults or 2.6 percent of the population age 18 or older in any given year have bipolar disorder. The condition typically starts in late adolescence or early adulthood, although it can show up in children and in older adults. People often live with the disorder without having it properly diagnosed and treated.