Genetics in Bipolar Disorder

Bipolar disorder is characterized by a period of manic and excitable behavior followed by a period of depression. For many, this disease can be treated with therapy and medication, but for some the mood swings can be so severe as to require hospitalization. Studies have shown a genetic link and predisposition to the disease, and research continues to further explore the genetics of bipolar disorder.

In the Genes

• Studies have shown that the disease is caused not by a single gene, but a combination on chromosomes 18, X, 11 and 21. Unlike simple dominant and recessive traits, the development of bipolar disorder is complex.

Hereditary Factors

• While we know there are genes associated with bipolar disorder, studies have also shown that these genes can be passed on from generation to generation.

Predisposition

• Studies have shown that two thirds of diagnosed bipolar disorders are caused by genetic factors, and a third by environment. Research continues to identify both the genetic and environmental factors.

Manic Versus Depression Prevalance

• While bipolar as a whole revolves around both the manic and depressed states, certain cultures have shown a predisposition to one state over another. For example, Amish and Mediterranean communities seem to be connected more to the manic state, while in Scandinavian cultures, depression is more prevalent.

Onset

• For those with environmental bipolar disorder, the onset of symptoms can be at any age. Genetic bipolar tends to manifest itself in the twenties and usually before 35. Diagnosis can be difficult because it can be linked to drug and alcohol abuse and other factors.