Four genes linked to increased risk of suicide

Hopkins scientists have discovered a small region of DNA associated with a increased risk for attempted suicide. The study, published in the journal Molecular Psychiatry, could lead to better suicide prevention and provide a new direction for research and drug development.

The study was led by Virginia L. Willour, an assistant professor of psychiatry and behavioral sciences at the School of Medicine. Her lab gathered DNA samples from 2,700 patients with bipolar disorder and studied the genetic differences between those who had and had not attempted suicide.

They patients were drawn from the Systematic Treatment Enhancement Program for Bipolar Disorder cohort, the Wellcome Trust Case Control Consortium bipolar cohort and the University College London cohort. Willour and her colleagues identified a small region on chromosome 2 that is associated with an increased risk for attempted suicide.

This small region contains four genes, including the ACP1 gene. Patients with an excess amount of the ACP1 protein in their brains were more likely to attempt to commit suicide.

Those with one replica of a genetic variant in the region of the ACP1 gene were 1.4 times more likely to attempt to commit suicide than those without, and those with two variants were three times as likely.

The ACP1 protein is thought to influence the same biological pathway as lithium, a medication known to reduce the rate of suicidal behavior.

“We have long believed that genes play a role in what makes the difference between thinking about suicide and actually doing it,” Willohur said in an interview with Newswise.com.

Willour and her colleagues were able to replicate their findings in another sample group. This group included more than 3,000 people with bipolar disorder.

By using patients with bipolar disorder, researchers 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.

Nearly 30,000 Americans commit suicide each year. It causes twice as many deaths as HIV/AIDS, and the CDC declared it the 11th leading cause of death in the U.S.

“Roughly 4.6 percent of the population has attempted suicide at least once,” Willour was quoted as saying in an interview with Newswise.com.

Suicide is a widespread occurrence in the U.S., as well as the rest of the world, and Willour believes that her findings are just one stride towards adequately treating potential patients.

The next step in her research is to determine how exactly these genetic differences increase the risk of attempted suicide.

“What’s promising,” Willour said to Newswise.com, “are the implications of this work for learning more about the biology of suicide and the medications used to treat patients who may be at risk.”