A genome-wide association study of thousands of people with bipolar disorder suggests that genetic risk factors may influence the decision to attempt suicide. Johns Hopkins scientists and an international team of collaborators, reporting online on March 22, 2011, in the journal Molecular Psychiatry, have identified a small region on chromosome 2 that is associated with increased risk for attempted suicide. This small region contains four genes, including the ACP1 gene, and the researchers found above normal levels of the ACP1 protein in the brains of people who had committed suicide. This protein is thought to influence the same biological pathway as lithium, a medication known to reduce the rate of suicidal behavior. The researchers said the findings could lead to better suicide prevention efforts by providing new directions for research and drug development. "We have long believed that genes play a role in what makes the difference between thinking about suicide and actually doing it," said study leader Dr. Virginia L. Willour, Ph.D., an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine. Dr. Willour and her colleagues studied DNA samples from nearly 2,700 adults with bipolar disorder, 1,201 of them with a history of suicide attempts and 1,497 without. They found that those with one copy of a genetic variant in the region of chromosome 2 where ACP1 is located were 1.4 times more likely to have attempted suicide, and those with two copies were almost 3 times as likely. Dr. Willour and her colleagues were able to replicate their findings in another group of samples: This one comprised DNA from more than 3,000 people with bipolar disorder.Login Or Register To Read Full Story