Genetic Breakthrough for Bipolar Disorder

Medical Reviewer

In what amounts to a scientific breakthrough a combined team of scientists from Britain and the United States have  located two genes linked to bipolar disorder. Professor Nick Craddock, of Cardiff University's school of medicine, who lead the research says, "the findings will help people to avoid saying bipolar is just the way some people are, or that they should be able to control it . . . it puts it on a parallel with other diseases, such as heart disease and diabetes."

In one of the largest research projects of its kind, genes from more than 10,000 people, including 4,300 with bipolar disorder were examined, constituting a review of around 1.8 million genetic variations. The research team then identified that people with bipolar disorder were significantly more likely to have variants of the ANK3 and CACNA1C genes. These genes help to make proteins that control the flow of calcium and sodium ions that move in and out of nerve cells.

The ANK3 gene has a role in controlling the activity of cells whereas the CACNA1C gene is responsible for channels that control calcium flow from the brain. Normal brain function relies on a delicate balance of sodium and calcium. "The brain operates according to how quickly calcium and sodium are going in and out of cells and how much of it goes in and out," Craddock said.

The study, reported in the journal of Nature Genetics, is not expected to be helpful in determining risk for the disorder. Many people have the genes but do not have bipolar disorder. What the findings do achieve is they put to rest the notion that bipolar is purely psychological in nature. The fact that the disorder can now be identified as physiological will also help to provide a focus for future research and give direction to new treatments. Although lithium is known to help, it only achieves benefits for two-thirds of people and can cause weight gain and shakiness.

In an upbeat assessment of work to date and speaking to journalist Madeline Brindley of the Western Mail, Professor Craddock stated:

"When the research team can identify bipolar as an illness, like any other caused by a genetic predisposition, the stigma and discrimination faced by people with bipolar may finally be able to become a thing consigned to the history books."