Bipolar Disorder Research: Searching for Genetic Links

In trying to determine the genes that contribute to bipolar disorder, researchers took a clue from Google. In the same way that search engines sift through millions of web pages to find those referencing a given topic and then ranking them by the number of relevant links -- researchers sifted through a multitude of studies on the human genome and separated out those genes with the most links to bipolar disorder.

The study, conducted by neuroscientists at the Indiana University School of Medicine and published in the American Journal of Medical Genetics, the first comprehensive map of genes likely to be involved in bipolar disorder. The findings both underscore the complexity of the disorder, and offer promise for future screening methods and treatment options.

"We now project that there will be hundreds of genes – possibly as much as 10 percent of the human genome – involved in this illness," explained Alexander B. Niculescu III, M.D., Ph.D., an assistant professor of psychiatry and director of the laboratory of neurophenomics at Indiana University School of Medicine. "Not all genetic mutations will occur in every individual with bipolar disorder. Different individuals will have different combinations of genetic mutations. This genetic complexity is most likely what made past attempts to identify genes for the disorder through genetic-only studies so difficult and inconsistent."

Dr. Niculescu, a practicing psychiatrist and a molecular geneticist, said this work opens exciting avenues for psychiatric researchers and clinicians, as well as for patients and their families. "Researchers now plan to study individuals to see which combination of genes is present in individuals to come up with a genetic risk score."

The goal, he said, is to be able to apply the risk score to test individuals even before the illness manifests itself for preventive measures – lifestyle changes, counseling, low-dose medications – or to delay or stop the illness from developing.