Bipolar disorder, or manic-depressive illness, is a group of disorders characterized by severe mood shifts or a mix of depression and high-energy phases known as manic episodes. There are unusual shifts in mood, energy, and ability to function. The symptoms of bipolar disorder are severe and can result in damaged relationships, poor job or school performance, and even suicide.
There are several different types of bipolar disorders. Bipolar I disorder refers to a condition in which an individual experiences a manic episode for at least one week and may or may not also experience depression. Bipolar II refers to the presence of a current or past hypomanic episode, which is a slightly less severe form of mania, and also the presence of a current or past episode of major depression.
A manic episode is a period of abnormally elevated or irritable mood that includes an abnormal increase in energy level, and lasts for at least one week. Additionally, a person experiencing mania may present with changes from their usual behavior, including a sudden inflation of self-esteem, a decreased need for sleep, a shift to being more talkative and easily distracted, and an involvement in activities that have high potential for painful consequences (gambling, heavy spending, sexual indiscretions).
A hypomanic episode refers to a period of abnormally elevated or irritable mood that includes an abnormal increase in energy level and lasts for at least four consecutive days. Hypomania is similar to mania in that the disturbance in mood and the change in functioning are observable by others, but the episode is not severe enough to cause major impairment in social or occupational functioning or to require hospitalization.
People experiencing a manic episode are often described as excessively cheerful or "feeling on top of the world." Often, however, the dominant mood during a manic episode is irritability, and people display hostility and angry tirades, particularly if an attempt is made to interrupt the individual. During a manic episode, an person may start several new projects and feel that they are capable of accomplishing anything, regardless of their level of experience or talent. One of the most common features of mania is a decreased need for sleep, and when the sleep disturbance is severe, a person might go days without sleep, yet not feel tired. Often, a manic person's thoughts race faster than they can be expressed through speech, and the result may be abrupt shifts from one topic to another or incoherent speech.
A long-term prospective study of children at risk for bipolar disorder (because a parent has the disorder) shows a developmental sequence of the disorder beginning in childhood with symptoms not specific to bipolar disorder, namely sleep problems and anxiety. It progresses to minor mood disorder and then, in adolescence, to major depressive disorder. Full-blown bipolar disorder develops in the transition to adulthood, usually heralded by an episode of mania or hypomania or a first episode of psychosis following an episode of depression.
About 5.7 million American adults, or about 2.6 percent of the population age 18 and older, in any given year have bipolar disorder. Bipolar disorder typically develops in late adolescence or early adulthood. However, some people have their first symptoms during childhood, and some develop them late in life. Bipolar disorders are typically chronic conditions and require lifelong management. More than 90 percent of people who have a single manic episode will go on to have recurrent episodes of mania or depression.
Bipolar disorder is often not recognized, and people may suffer for years before it is properly diagnosed and treated. In fact, people who are currently experiencing mania often don't perceive that they are ill or in need of treatment and will resist engaging with treatment. Treatment is incredibly important, however, considering that the lifetime risk of suicide among individuals with bipolar disorder is at least 15 times that of the general population.