The largest genetic study of suicide ever conducted has discovered 12 new risk factors.

The study, conducted by several worldwide institutions including the University of Utah School of Medicine and the Huntsman Mental Health Institute, identified 12 DNA variations in the human genetic code associated with the risk of attempting suicide.

The study highlights genetic links between factors that influence physical and behavioral health and suicide attempts. Some of those factors include smoking, chronic pain, attention-deficit/hyperactivity disorder, impulsivity, pulmonary conditions and heart disease.

The findings of the study, published online Sunday in the American Journal of Psychiatry, suggest that some of the genetic underpinnings of suicide are shared with those conditions.

“Many people who die from suicide have significant health conditions associated with that risk,” said Anna Docherty, corresponding author of the study and associate professor of psychiatry at Huntsman Mental Health Institute at the University of Utah. “If we can use genetic information to characterize the health risks of those who attempt suicide, we can better identify those patients who need contact with the mental health care system.”

Docherty said no single gene causes suicide, but the cumulative effect of many different genes does influence a person’s risk.

“In psychiatry, we have many tiny genetic effects. But when we account for all of them together, we start to see a real genetic risk signal,” she said.

The researchers analyzed data from 22 different populations around the world and identified genetic variations more common among people who have attempted suicide. This included 43,871 documented suicide attempts and 915,025 ancestry-matched controls, making it the largest genetic study of suicide to date.

Researchers compared all variants with previously published genetic data on more than 1,000 other traits and disorders, including physical conditions, behaviors and psychiatric conditions. They determined that genetic variants linked to suicide are also linked to other health conditions.

“That allowed us to look at how genetic risk for suicide overlaps with genetic risk for depression, heart disease and many other risk factors,” Docherty said. “It showed significant overlap with mental health conditions, but also a lot of physical health conditions, particularly for smoking and lung-related illnesses. This is something we can’t necessarily see in medical records of people who die from suicide.”

Hillary Coon, study co-author and professor of psychiatry at the Huntsman institute, said the results don’t mean that people with any of the listed health factors are at high risk for attempting suicide. Rather, combining the genetic predisposition with other stressors such as life circumstances, traumatic events and health conditions could increase the risk.

The scientists said additional studies will need to be done to determine whether the variants directly or indirectly impact suicide risk and, if so, how.

“We want to start to explore the biological underpinnings that are common across suicide and these health factors, because that will lead to the most convincing drug targets,” Docherty said, adding the fact that understanding how suicide is linked to other health conditions could open doors to new ways of assessing and treating a person’s suicide risk.

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