Sign Up for a Free Account
  • Updated 04.20.2019
  • Released 04.20.2019
  • Expires For CME 04.20.2022

Bipolar disorder


This article includes discussion of bipolar disorder, manic depression, bipolar type I, and bipolar type II. The foregoing terms may include synonyms, similar disorders, variations in usage, and abbreviations.


Bipolar disorder, or manic depression, is a serious mental illness that may drastically affect an individual’s ability to function because of mood instability. Given the unpredictability of severe high (mania) and severe low (depression) mood states, people with bipolar disorder may struggle with social and workplace settings. Bipolar disorder affects mood, sleep, concentration, and reasoning. Some individuals may experience psychosis or may struggle with suicidal thoughts. Although the underlying cause of bipolar disorder is not clear, research in neurobiology and genetics provides some insight into this complex illness. Treatment of the disorder is primarily with mood stabilizers, but often requires additional adjunctive medications. Additionally, psychosocial support and therapy are essential for maintaining stability. This article aims to provide distinction between bipolar disorder subtypes and includes updates on the current research regarding the underlying pathology as well as guidance on the pharmacologic treatment of the illness.

Key points

• Bipolar disorder may be diagnosed after a single manic episode.

• Patients will often experience a combination of depressive, manic, and hypomanic episodes throughout the course of illness.

• The severity and frequency of mood symptoms vary among individuals.

• The role of treatment is to stabilize mood and decrease the severity and frequency of mood episodes.

Historical note and terminology

Manic depression was first noted by ancient Greek scholars, including Hippocrates, and the term “mania” is derived from the Greek word for “madness” (12). The idea of a madness related to one’s mood persisted until near the end of the 19th century when Emil Kraeplin distinguished between manic-depressive psychosis and dementia praecox (modern schizophrenia) (38). The idea of an illness with 2 distinct affective poles, mania and depression, was introduced by Karl Leonhard in the 1950s (25). Today, bipolar disorder is recognized as a serious mental illness within the Diagnostic and Statistical Manual of Mental Disorders.

This is an article preview.
Start a Free Account
to access the full version.

  • Nearly 3,000 illustrations, 
including video clips of 
neurologic disorders.

  • Every article is reviewed by our esteemed Editorial Board for accuracy and currency.

  • Full spectrum of 
neurology in 1,200 
comprehensive articles.

Questions or Comment?

MedLink, LLC

10393 San Diego Mission Rd, Suite 120

San Diego, CA 92108-2134

Toll Free (U.S. + Canada): 800-452-2400

US Number: +1-619-640-4660