Scientists identify genetic link to suicide attempts

A new study suggests that genetic risk factors may influence the decision to attempt suicide.

Johns Hopkins scientists 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 more than 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.

Study leader Virginia L. Willour, an assistant professor of psychiatry and behavioral sciences, 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 three times as likely.

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. By using only DNA from people with bipolar disorder, the researchers say they were able to control for mental illness and narrow in on what may cause one group to attempt suicide and another to control those urges.

The study is reported in the journal Molecular Psychiatry.