In hindsight, it can often seem like there were many clues to what might have led someone to commit suicide. But what if there were hidden indicators you could spot before someone made an attempt on their life? In what is sure to be highly controversial research, a new study claims to be able to predict a person's risk of committing suicide with over 90% accuracy, using only a blood test coupled with a questionnaire.

According to the researchers from Indiana University School of Medicine, they have developed a simple test that looks for 11 biomarkers in a patient’s blood. When they coupled this with an app-based questionnaire, they say they were able to predict which individuals in a group of patients already being treated for psychiatric disorders would go on to develop suicidal thoughts over a period of two years.

“We believe that widespread adoption of risk prediction tests based on these findings during healthcare assessments will enable clinicians to intervene with lifestyle changes or treatments that can save lives,” said co-author Alexander B. Niculescu III, a professor of psychiatry and medical neuroscience, in a statement. The study has been published in Molecular Psychiatry.  

But not all scientists are convinced by this, with questions being raised about the size of the study, as just over 200 men were involved. The small sample size means that it’s easy to skew results when considering rare conditions. Another suggested problem is that if any such test was to be used on the wider public, the number of false positives – results claiming someone does have suicidal tendencies when they don’t – would simply be too high. Add to this the many different environmental and behavioral factors that are thought to increase the risk of suicide, and many remain far from persuaded by these results.      

Despite being highly contended, there has still been a growing interest in using biomarkers to predict mental health. Only last year there was a similar study that claimed a single genetic marker called SKA2 could predict suicide risk, though this conclusion was accused of being far too simplistic. This new study looked at a far wider range of biomarkers and tracked how their levels changed over a period of a few years in patients being treated for a range of disorders, from bipolar to schizophrenia. In addition to this, they then analyzed blood samples from 26 men who had succeeded in committing suicide.

In recent years, suicide rates have been climbing in many countries. It is currently one of the leading causes of death amongst men under the age of 35 in the U.K., and is currently at an all-time high in the U.S., with one person committing the act every 12.8 minutes. This makes it a very real problem that requires a better system to predict when someone might be at risk of suicide.