Genetic liability for depression increases suicide attempt risk, study says

June 11 (UPI) -- Having suicidal tendencies may stem from genetic disposition, new research shows.

People who have attempted suicide hold a higher genetic liability for depression regardless of the psychiatric disorder they have, according to a study published this month in The American Journal of Psychiatry.

"Like many psychiatric disorders, suicide attempt is known to have a partially genetic underpinning and genetic studies can provide invaluable insights into the underlying biology," Niamh Mullins, a researcher at The Mount Sinai Hospital and study author, said in a news release. "Through the collective efforts of many researchers, we analyzed the genomes of suicide attempters and non-attempters across three major psychiatric disorders. Our data showed that suicide attempters with major depressive disorder, bipolar disorder or a schizophrenia diagnosis carry a greater genetic liability for major depression than non-attempters."

Using data from the Psychiatric Genomics Consortium, the researchers compared the genomes of 6,569 people who attempted suicide and 17,232 people who did not attempt suicide but have major depressive disorder, bipolar disorder, or schizophrenia.

The researchers then merged the samples with 46 cohorts in Australia, Europe and the United States. The researchers used polygenic risk scores to figure the genetic liability to depression.

Each year, suicides and suicide attempts cost the United States roughly $70 billion for lifetime medical and work-loss costs, according to the Centers for Disease Control and Prevention.

"These results indicate the existence of a shared genetic etiology between suicide attempt and major depression that is common to suicide attempt in different psychiatric disorders," Mullins said.

The goal, researchers say, is to find biological mechanisms that indicate suicide risk and develop treatment methods that may prevent suicide deaths, in additional to easing the burdens carried by patients, families and healthcare systems.

"Our study is the first consortium-based GWAS on suicide attempt and makes significant progress in increasing numbers by combining samples across clinical cohorts. However, further collaborative efforts to amass samples on an even larger scale will be essential to identify specific genetic variants which play a role in increasing risk of suicide attempt," Mullins said.