Bipolar disorder is a medical disorder with strong psychological impacts. It was once known as manic-depressive psychosis.
Three basic forms of the disorder are observed: one in which the resulting dominant psychological state is depression, one in which the dominant state is a highly elevated mood, and one in which these states frequently alternate. In all three forms at least one manic state occurs. The mood changes are also far more severe than in other
disorders involving mood swings. In the manic phase a person is inappropriately optimistic and grossly overestimates his or her positive attributes, shows speeded movement and speech, undergoes intellectual disorganization, and has pathologically bad judgment. In the depressive phase a person exhibits slowed speech and movements in addition to depression. In either phase it is not unusual for hallucinations, delusions, or both to occur.
Bipolar disorder develops at least once in about 0.5 to 1% of the population. The first episode usually takes place in persons in their twenties, and it occurs equally in both sexes. Its causes are unknown but may be rooted in some genetic defect. Stressful life experiences may be contributing factors but do not seem to trigger its onset. In some 15 to 20% of people with untreated mood disorders, the condition may be fatal. Lithium salts (see lithium, drug) are a common medical
treatment, but side effects of this drug can be severe. Newer drugs such as Prozac and Anaframil have also shown promise. Even without treatment perhaps 85 percent of the persons with the disorder survive, but without treatment most of them will not be fully functional.