Research reveals suicide may be hereditary

By Stephen Beech via SWNS

Suicide may be hereditary, according to new research.

The study of members of the American military identified four genes as heightening the risk of suicidal thoughts and actions.

While more work is needed to determine whether the identification of the genetic markers might lead to targeted treatments, scientists say their findings advance the understanding of how inherited risk factors play a role in the pathology of suicidal thoughts and behavior.

Study co-lead author Professor Nathan Kimbrel, of Duke University, NC, said: “It’s important to note that these genes do not predestine anyone to problems, but it’s also important to understand that there could be heightened risks, particularly when combined with life events."

Prof Kimbrel and his colleagues conducted a large, genome-wide analysis using data from more than 630,000 US military veterans. Of the participants, 71.4 percent were of European ancestry; 19.1 percent of African ancestry; 8.1 percent were Hispanic; and 1.3 percent were Asian. Most of the participants were men.

Within that group of veterans, 121,211 cases of suicidal thoughts or actions were identified from medical records. Participants were classified as controls if they had no documented lifetime history of self-harming behavior.

Through a genome-wide analysis of blood samples, the research team identified several genes that were evident among participants with documented cases of suicidal thoughts or actions, regardless of their ancestral background.

Four genes had the strongest links, and have been previously associated with psychiatric conditions.

One of them ESR1, an estrogen receptor, has been previously identified as a causal genetic driver gene of PTSD and depression, which are risk factors for suicidal behavior among veterans.

Estrogen is also suspected as a cause of sex differences in depression rates, and loss of ESR1 has been found to produce effects on brain tissue in men.

The second gene identified was DRD2, a dopamine receptor, which has previously been associated with suicide attempts, schizophrenia, mood disorders, ADHD, risky behaviors, and problem drinking.

The third, DCC, is expressed in brain tissue, and has been associated with multiple psychiatric conditions and is elevated in the brains of people who die by suicide.

The fourth suicide-related gene identified, TRAF3, is associated with antisocial behavior, substance abuse, and ADHD.

Prof Kimbrel said that lithium - a "gold standard" treatment for bipolar disorder shown to reduce suicide risk - modulates the expression of TRAF3 and several other inflammatory genes.

In addition to those four genes, the research team also identified nine additional ancestry-specific risk genes.

Prof Kimbrel added: "While genes account for a small amount of risk relative to other factors, we need to better understand the biological pathways that underly a person’s risk for engaging in suicidal behavior.

“Suicide is the cause of over 700,000 deaths annually and is the fourth-leading cause of death among people aged 15 to 29 years old."

"The more we know, the better we can prevent these tragic deaths.”

The findings were published in the journal JAMA Psychiatry.