Washington: A simple blood test can soon reliably predict a person's risk of attempting suicide, significant research reveals.
This may be possible because researchers at Johns Hopkins University have discovered a chemical alteration in a single human gene linked to stress reactions.
The changes in this gene - involved in the function of the brain's response to stress hormones - plays a significant role in the reaction to the daily strain into suicidal thoughts and behaviours.
During experiments, researchers focused on a genetic mutation in a gene known as SKA2.
By looking at brain samples, the researchers found that in samples from people who committed suicide, levels of SKA2 were significantly reduced.
"With this test, we may be able to stem suicide rates by identifying those people and intervening early enough to head off a catastrophe," said study leader Zachary Kaminsky, an assistant professor at Johns Hopkins University's school of Medicine.
Within this common mutation, researchers found in some subjects an epigenetic modification that altered the way the SKA2 gene functioned without changing the gene's underlying DNA sequence.
The modification added chemicals called methyl groups to the gene.
Higher levels of methylation were then found in the same subjects who had killed themselves.
Next, researchers tested three different sets of blood samples.
The largest one involving 325 participants found similar methylation increases at SKA2 in individuals with suicidal thoughts or attempts.
They then designed a model analysis that predicted which of the participants were experiencing suicidal thoughts or had attempted suicide with 80 percent certainty.
Those with more severe risk of suicide were predicted with 90 percent accuracy.
In the youngest data set, they were able to identify with 96 percent accuracy whether or not a participant had attempted suicide, based on blood test results.
"We have found a gene that could be really important for consistently identifying a range of behaviours from suicidal thoughts to attempts to completions," Kaminsky noted.
"We might soon be able to monitor the blood to identify those at risk of suicide," he added in a paper appeared online in The American Journal of Psychiatry.