While there are a wide range of scenarios that may cause a person to take their own life, the fact is that in a given situation, some people will do so whereas others won't. Scientists at the Johns Hopkins University School of Medicine now believe that this difference can largely be traced to a genetic mutation in the people who are more likely to commit suicide. What's more, this mutation can be detected via a blood test.

The research team, led by Dr. Zachary Kaminsky, analyzed brain samples from the cadavers of both mentally ill and healthy people. In cases where the people had died by suicide, there was a lower-than-normal concentration of a gene known as SKA2. It plays a part in the brain's handling of stress hormones, and if it isn't functioning properly or is lacking, stressful situations that would ordinarily be bearable can drive a person to contemplate or even attempt killing themselves.

It was also found that the mutation not only reduced the levels of the gene, but also added chemicals called methyl groups to the SKA2 that was present.

This finding was backed up by an analysis of blood samples taken from 325 living test subjects. Based on the levels of methyl groups in the SKA2 genes within those samples, the scientists could predict with 80 percent overall accuracy which of the participants had contemplated or attempted suicide. The accuracy went up to 90 percent for test subjects who posed a severe suicide risk, and 96 percent for the youngest group of participants.

If the data is confirmed by larger studies, it is hoped that such testing could ultimately be used to predict how likely mentally-ill people are to commit suicide, and to then tailor their treatment accordingly. It could also be utilized to screen patients before administering medication that can cause suicidal thoughts, or as a reference for monitoring people who have recently returned from stressful military service.

A paper on the research was recently published in The American Journal of Psychiatry.