Scientists are finding more accurate ways to predict if an individual is at risk of committing suicide. At this time, diagnosis still relies largely on clinicians’ impressions and patients’ self-reported symptoms. Many people will not answer truthfully when asked “Are you suicidal?” so it is necessary to develop a more accurate test in the interest of saving lives.
Researchers at the Johns Hopkins University School of Medicine have discovered that a patient’s risk for suicide could be determined by a simple and objective blood test. They looked at a gene called SKA2, which is involved in the brain’s response to the stress hormone cortisol. When a healthy person gets stressed, the cortisol levels in his/her brain shoot up, but eventually decrease. When a person who is at greater risk of suicide gets stressed, the levels of cortisol in the brain are higher, do not decrease as easily.
In an examination of brain samples of mentally ill and healthy people, researchers found that the SKA2 levels were much lower in those who had died by suicide. This was related to an epigenetic change (change in gene expression) that added chemicals called methyl groups to the gene. The methyl groups acted like dimmer switches and were turning down the levels of SKA2. In another part of the study, they took blood samples from the living participants. Those who had experienced suicidal thoughts or made attempts showed methylation increases in the same gene. Researchers could predict which participants were experiencing suicidal thoughts or had attempted suicide with 80 per cent accuracy.
While this is an important breakthrough in suicide risk assessment, the researchers caution that there are still many questions to be answered, such as how the gene might change over time. Researchers also want to be clear that their findings are not 100% deterministic. While the gene represents a vulnerability to stress, there could be other factors involved in whether or not a person will commit suicide.