Scientific studies have identified numerous genes associated with different conditions, from autism or ADHD, to obesity or depression. Now, new research has found that people who attempt suicide are not only influenced by experiences and emotions, such as traumatic situations or stress, but there are also hereditary genetic factors that can drive suicidal behavior.
Researchers have identified 12 DNA variants, or variations in the human genetic code, that are associated with the risk of attempting suicide, and their findings reveal genetic links between suicide attempts and factors that influence physical and behavioral health. including impulsivity, smoking, chronic pain, ADHD, and lung and heart disease. The results have been published in the American Journal of Psychiatry and suggest that some of the genetic underpinnings of suicide are shared with these conditions.
“Many people who die by suicide have significant health problems associated with that risk,” said Anna Docherty, an author of the study and an associate professor of psychiatry at the Huntsman Mental Health Institute at the University of Utah. “If we can use genetic information to characterize the health risks of suicide attempters, we will be able to better identify patients who need contact with the mental health care system,” she notes.
Genetic risk for suicide showed significant overlap with mental health conditions, but also with many physical health conditions, such as smoking and lung diseases
The information provided by the new study could help better understand the biological causes of suicide to improve prevention strategies, and even so that medical professionals would be able to identify people who may need mental health support because they are at higher risk. of presenting suicidal ideation.
Genetic predisposition and other factors that increase the risk of suicide
The research has been conducted by scientists from HMHI (Huntsman Mental Health Institute at the University of Utah), the Icahn School of Medicine at Mount Sinai, the Duke University School of Medicine, the Veterans Affairs Health Care System of Durham and Vanderbilt University Medical Center who led the collaboration with multiple institutions around the world. These scientists analyzed data from 22 different populations around the world, which included people of different ancestral and ethnic origins.
The researchers used statistical methods on the data and identified genetic variations that are more common among people who have attempted suicide. The new analysis combines data from the Million Veterans Program (MVP) and the International Suicide Genetics Consortium (ISGC), including 43,871 documented suicide attempts and 915,025 ancestry-matched controls, making it the largest genetic study of suicide. big to date.
The analysis identified new genetic variants that correlated with suicide attempts. The researchers then compared all the variant signals with previously published genetic data on more than 1,000 traits and disorders, including psychiatric pathologies (e.g., ADHD), physical health problems (e.g., heart disease), and behaviors (e.g., smoking), and determined that genetic variants linked to suicide attempts 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 explained. “It showed significant overlap with mental health conditions, but also with many physical health conditions, particularly smoking and lung-related diseases. “This is something we can’t necessarily see in the medical records of people who die by suicide.”
As the researcher points out, no gene alone causes suicide, but rather it is the cumulative effect of many different genes that influences the risk of a person attempting to take their own life. “In psychiatry we have a lot of tiny genetic effects, but when we take them all together we start to see a real genetic risk signal,” she says.
The results do not mean that people with any of these conditions are at high risk for attempting suicide, says Hillary Coon, study co-author and professor of psychiatry at HMHI. But combining genetic predisposition with other stressors (which could include other genetic risk factors, health problems, life circumstances or traumatic events) could increase that risk, she explains.
Initial analyzes support the idea that many of the DNA variants the scientists identified are located in genes with known biological functions, reinforcing the hypothesis that changes in these genes could affect a person’s physiology or behavior. Several of the genes control processes in cells, such as managing cellular stress, repairing damaged DNA, and communicating with the immune system. Most are also highly expressed in the brain and are known targets of antipsychotic and antidepressant drugs.
New studies are needed to determine whether the variants have a direct or indirect effect on the risk of suicide, and how, because what has been demonstrated so far is an association, and not cause and effect. Understanding how suicide is related to other health conditions could help develop new strategies to assess (and treat) suicide risk, Docherty adds. “We want to start exploring the biological underpinnings that are common between suicide and these health factors, because that will lead to the most effective drug targets,” she concludes.
