The likelihood of developing bipolar disorder depends in part on the combined, small effects of variations in many different genes in the brain, none of which is powerful enough to cause the disease by itself, a new study shows. However, targeting the enzyme produced by one of these genes could lead to development of new, more effective medications. The research was conducted by scientists at the National Institutes of Health's National Institute of Mental Health (NIMH), with others from the Universities of Heidelberg and Bonn and a number of U.S. facilities collaborating in a major project called the NIMH Genetics Initiative.
The study is the first to scan virtually all of the variations in human genes to find those associated with bipolar disorder. Results were published online May 8 in Molecular Psychiatry by Amber E. Baum, PhD, lead researcher Francis J. McMahon, MD, and colleagues.
"This is an example of how advances in genetics research feed into practical applications. This research would not have been possible a very few years ago. We now have a new molecular target scientists can investigate in their search for better medications for bipolar disorder," said NIH Director Elias A. Zerhouni, MD.
About 5.7 million American adults have bipolar disorder, which also is called manic-depressive illness. Symptoms include extremes in mood, from pronounced over-excitement and elation, often coupled with severe irritability, to depression. Children also may have the condition, usually in a more severe form than adults.
"We're beginning to get a foothold on the genetics of this complex brain disorder," said NIMH Director Thomas R. Insel, MD.
Most people occasionally have mood swings, but the shifts that occur in bipolar disorder, and the changes in behavior and energy level that accompany them, are sometimes disabling. Lithium and the other mood-stabilizing medications used to treat the condition help many pati
Contact: Susan Cahill
NIH/National Institute of Mental Health