Overview of Bipolar Disorder

Bipolar disorder, or manic-depressive disorder, is a mood disorder in which people experience alternating episodes of mania and major depression. Mania is characterized by elation, irritability, excitability, racing thought and speech, and hyperactivity. Major depression is characterized by sadness, withdrawal, despair, and suicidal thoughts.

In the early 1900s, the German psychiatrist Emil Kraeplin was the first to formally describe bipolar disorder. He used the term "manic depressive" to explain how mania and depression both affect the patient. His work in the early 20th century led to advancements in classifying, treating, and predicting the course of mental illness, which ushered in the formal discipline of psychiatry.

Bipolar disorder has two distinct classifications:

  • Bipolar I: history of major depression and at least one episode of mania
  • Bipolar II: history of major depression and much less severe episodes of mania (hypomania)

Bipolar I

An onset before the age of 30 usually results in frequent, severe episodes. Psychosis is more common in this group and symptoms tend to linger between episodes. An onset after the age of 40 has a better prognosis. Generally, short episodes, late onset, the absence of other medical or psychiatric conditions, and early treatment have a better prognosis.

Most people are symptom free for months or even years between episodes of depression and mania. Approximately 25% of people never fully recover from an episode. Nearly 33 percent of people have great difficulty functioning at work and in social settings.

Three-fourths of manic episodes occur before or right after a major depressive episode. After the first manic episode, there's a 90% chance that a second one will occur. Typically, a greater number of manic episodes are experienced over a lifetime. Approximately 40 percent of people with bipolar disorder have an average of one episode every 2 1/2 years, or four in every 10 years.

Bipolar II

People with bipolar II disorder experience major depressive episodes that alternate with hypomania (milder manic episodes). During hypomanic episodes, patients may become more productive or noticeably goal driven, but their ability to function well in their normal daily activities is not impaired.

About 10 percent of people who experience hypomanic episodes eventually have manic episodes.

Incidence & Prevalence of Bipolar Disorder

According to the National Institute of Mental Health, bipolar disorder affects more than 5.7 million adults in the United States each year. Approximately 3 percent of people in the United States are affected. The age of onset is usually the late teens or early 20s and there is a history of depression in most cases.

Men and women are affected in equal numbers. Women's first episode is typically manic, while men typically experience a depressive episode first.

Hospitalization for Bipolar Disorder

Hospitalization is required for severe episodes of mania and depression to protect patients from injuring themselves or others.

Electroconvulsive therapy (ECT) is used primarily as an acute treatment for hospitalized patients who are suicidal, psychotic, or dangerous to others. It is effective in nearly 75 percent of patients who undergo this treatment. Receiving ECT during pregnancy is considered safe.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 01 Feb 2001

Last Modified: 20 Jun 2013