Bipolar disorder is a mental health condition that causes extreme shifts in mood, energy, and behavior. This disorder most often appears in late adolescence or early adulthood, although symptoms can begin at any time of life.

People with bipolar disorder experience both dramatic "highs," called manic episodes, and "lows," called depressive episodes. These episodes can last from hours to weeks, and many people have no symptoms between episodes.

Manic episodes are characterized by increased energy and activity, irritability, restlessness, an inability to sleep, and reckless behavior. Some people with bipolar disorder experience hypomanic episodes, which are similar to but less extreme than manic episodes.

Depressive episodes are marked by low energy and activity, a feeling of hopelessness, and an inability to perform everyday tasks. People with bipolar disorder often have repeated thoughts of death and suicide, and they have a much greater risk of dying by suicide than the general population.

Manic and depressive episodes can include psychotic symptoms, such as false perceptions (hallucinations) or strongly held false beliefs (delusions). Mixed episodes, which have features of manic and depressive episodes at the same time, also occur in some affected individuals.

Bipolar disorder is classified into several types based on the mood changes that occur. Bipolar I involves manic episodes, which can be accompanied by psychotic symptoms, and hypomanic or depressive episodes. Bipolar II involves hypomanic episodes and depressive episodes. Cyclothymic disorder involves hypomanic episodes and depressive episodes that are typically less severe than those in bipolar I or bipolar II.

Bipolar disorder often occurs with other mental health conditions, including anxiety disorders (such as panic attacks), behavioral disorders (such as attention-deficit/hyperactivity disorder), and substance abuse.

Bipolar disorder is a common form of mental illness. At some point during their lifetime, 2.4 percent of people worldwide and 4.4 percent of people in the United States are diagnosed with this condition.

Very little is known for certain about the genetics of bipolar disorder. Studies suggest that variations in many genes, each with a small effect, may combine to increase the risk of developing the condition. However, most of these genetic variations have been identified in single studies, and subsequent research has not verified them. It is unclear what contribution each of these changes makes to disease risk. Some of the genetic changes associated with bipolar disorder have also been found in people with other common mental health disorders, such as schizophrenia. Understanding the genetics of bipolar disorder and other forms of mental illness is an active area of research.

Studies suggest that nongenetic (environmental) factors also contribute to a person's risk of developing bipolar disorder. Stressful events in a person's life, such as a death in the family, can trigger disease symptoms. Substance abuse and traumatic head injuries have also been associated with bipolar disorder. It seems likely that environmental conditions interact with genetic factors to determine the overall risk of developing this disease.

Genetic Testing Information

• Genetic Testing Registry: Major affective disorder 1
• Genetic Testing Registry: Major affective disorder 7

Patient Support and Advocacy Resources

• National Organization for Rare Disorders (NORD)

Clinical Trials

• ClinicalTrials.gov

Catalog of Genes and Diseases from OMIM

• MAJOR AFFECTIVE DISORDER 1; MAFD1
• MAJOR AFFECTIVE DISORDER 2; MAFD2
• MAJOR AFFECTIVE DISORDER 5; MAFD5
• MAJOR AFFECTIVE DISORDER 6; MAFD6
• MAJOR AFFECTIVE DISORDER 8; MAFD8
• MAJOR AFFECTIVE DISORDER 7; MAFD7
• MAJOR AFFECTIVE DISORDER 9; MAFD9
• MAJOR AFFECTIVE DISORDER 3; MAFD3
• MAJOR AFFECTIVE DISORDER 4; MAFD4

Scientific Articles on PubMed

• PubMed

• Craddock N, Sklar P. Genetics of bipolar disorder. Lancet. 2013 May 11;381(9878):1654-62. doi: 10.1016/S0140-6736(13)60855-7. Citation on PubMed
• Goes FS. Genetics of Bipolar Disorder: Recent Update and Future Directions. Psychiatr Clin North Am. 2016 Mar;39(1):139-55. doi: 10.1016/j.psc.2015.10.004. Citation on PubMed
• Merikangas KR, Jin R, He JP, Kessler RC, Lee S, Sampson NA, Viana MC, Andrade LH, Hu C, Karam EG, Ladea M, Medina-Mora ME, Ono Y, Posada-Villa J, Sagar R, Wells JE, Zarkov Z. Prevalence and correlates of bipolar spectrum disorder in the world mental health survey initiative. Arch Gen Psychiatry. 2011 Mar;68(3):241-51. doi: 10.1001/archgenpsychiatry.2011.12. Citation on PubMed or Free article on PubMed Central
• Shinozaki G, Potash JB. New developments in the genetics of bipolar disorder. Curr Psychiatry Rep. 2014 Nov;16(11):493. doi: 10.1007/s11920-014-0493-5. Citation on PubMed
• Szczepankiewicz A. Evidence for single nucleotide polymorphisms and their association with bipolar disorder. Neuropsychiatr Dis Treat. 2013;9:1573-82. doi: 10.2147/NDT.S28117. Epub 2013 Oct 11. Citation on PubMed or Free article on PubMed Central