May also be called: Manic Depression; Manic-Depressive Disorder; Manic-Depressive Illness; Bipolar Mood Disorder; Bipolar Affective Disorder

Bipolar disorder is a type of mood disturbance characterized by episodes of low-energy depression (symptoms include sadness, fatigue, and hopelessness) and high-energy mania (signs include increased energy, sleep loss, and reckless behavior).

More to Know

Bipolar disorder is a type of depressive disorder, a medical condition that affects the way a person's brain functions. Someone with bipolar disorder will go through episodes of mania and at other times experience episodes of depression.

Doctors aren't sure exactly what causes bipolar disorder, but they believe it's linked to imbalances in certain brain chemicals called neurotransmitters. If the neurotransmitters aren't in balance, the brain's mood-regulating system won't work the way it should.

Often, episodes of mania or depression last for weeks or months, but they can change rapidly, even during the course of a day. During manic episodes, a person with bipolar disorder may have increased energy and activity, an elevated mood, racing thoughts, difficulty concentrating, and less need for sleep. He or she may also exhibit poor judgment and engage in reckless or aggressive behavior.

Periods of depression are marked by a loss of energy, prolonged sadness, feelings of guilt or worthlessness, sleeping and eating problems, and thoughts of death or suicide.

Treatment for bipolar disorder typically involves the use of medications, such as mood stabilizers, along with counseling or psychotherapy.

Keep in Mind

There's no cure for bipolar disorder, but most people who have it can be helped if a psychiatrist or psychologist diagnoses the disorder. Without treatment, bipolar disorder can get worse, but by following a treatment plan and making a few lifestyle changes — such as reducing stress, eating well, and getting enough sleep and exercise — people living with bipolar disorder can usually control their symptoms and lead normal lives.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.