What Are the Causes of Bipolar Disorder? Links to Genetics

Bipolar Disorder & Genetics

Bipolar disorder tends to run in families, as such researchers are looking for specific genes that may increase a person's chance of developing the illness. Genes are the "building blocks" of heredity. They help control how the body and brain work and grow. Genes are contained inside a person's cells that are passed down from parents to children.

Children with a parent or sibling who has bipolar disorder are four to six times more likely to develop the illness, compared with children who do not have a family history of the illness. However, most children with a family history of manic-depression will not develop the bipolar.

Advances in technology have aided researches to go more in depth of Genetic connection. The research is now much quicker and more far-reaching than in the past. One example is the launch of the Bipolar Disorder Phenome Database. This database, will allow scientists to link visible signs of bipolar with the genes that may influence them. With the aid of this database, researchers have found that most people with bipolar had:

• Missed work because of their illness


• Other illnesses at the same time, especially alcohol and/or substance abuse and panic disorders


• Been treated or hospitalized for bipolar.

The researchers also identified certain traits that appeared to run in families, including:

• History of psychiatric hospitalization


• Co-occurring obsessive-compulsive disorder (OCD)


• Age at first manic episode


• Number and frequency of manic episodes

Traits found in this study, may help researches find the genes that cause bipolar disorder some day. However, genes are not the only risk factor for manic-depression. Studies of identical twins have shown that the twin of a person with bipolar illness does not always develop the disorder. This is important because identical twins share all of the same genes. The study results suggest factors besides genes are also at work. Rather, it is likely that many different genes and a person's environment are involved. However, scientists do not yet fully understand how these factors interact to cause bipolar.

A recent study in germany suggests that rare sponteous mutations are a vital contributor to risk for bipolar as other brain related physicatric diseases, such as schizophrenia. The study also concluded that there is a strong association of rare de novo copy-number-variants or (CNV's) with bipolar. The rare de novo CNV's infuence the age of when bipolar disorder begins. The same instances were found in schizophrenia earlier studies. Although unclear the role of CNVs in bipolar disorder, the study suggests mood disorders could be evident for de novo mutations.