Blood Test Predicts Suicide Risk with 80-90% Accuracy
Could a specific gene mutation tell us with near-certainty who will attempt suicide? Researchers at Johns Hopkins Medicine published the results of a study which found that a simple blood test could alert health care providers to suicide risk with an astonishing level of accuracy.
In the study, the researchers found that people who attempt suicide or experience suicide ideation tend to have a mutation in the gene called SKA2. Their hypothesis formed when they studied the genomes of people who had died by suicide and found that their SKA2 levels were significantly reduced. "SKA2 has been implicated as important for the normal function of stress receptors," said study leader Zachary Kaminsky, an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine. "It chaperones them, and it goes up when glucocorticoid binds to these receptors, which happens when you get stressed out." To clarify, while the mutation is a relatively effective predictor of suicide risk, not everyone who attempts suicide has this mutation.
The mutation is epigenetic, or it affects the expression of the genes without involving a change in the genetic sequence itself. It changes the expression of the SKA2 gene by adding methyl groups to the gene. Higher methylation, in turn, predicts a higher risk for suicidal tendencies. "[Methyl groups] are basically molecular markers that are connected to genes that act like light switches or dimmer switches," Kaminsky said. "They are independent of the DNA sequence, but they can turn up or down a gene." A combination of brain and blood tests in 325 patients served to confirm this correlation. The researchers were able to predict with 80% accuracy whether the patient had experienced suicidal thoughts or an attempted suicide. They were able to identify the patients with particularly high risk for suicidal tendencies with 90% accuracy, and were able to predict past suicide attempts with 96% accuracy in a younger group of subjects.
[It's hard not to think of movies like Gattaca when you read research like this]
(Credit: Columbia Pictures)
The researchers emphasize that the gene is less a predictor of suicide risk and more an indicator of a dysregulated stress response, which multiple studies have shown is linked to suicidal ideation. It is the vulnerability to stress, rather than the gene itself, that is a meaningful predictor of suicide attempts. From the paper in the American Journal of Psychiatry: "SKA2 significantly interacted with anxiety and stress to explain about 80% of suicidal behavior and progression from suicidal ideation to suicide attempt."
While the clinical applications of this study are undoubtedly significant to the treatment of the mentally ill, there are also potentially insidious implications, particularly as a result of the gene's relationship to stress. If a person's genome can show that he or she is more vulnerable to stress, then they may be more likely to receive necessary mental health intervention, but they may also be more likely to experience genetic discrimination. This study, and others like it, could open the door to the possibility of a Gattaca-like dystopian future in which every person is relegated to certain jobs based on their genetic ability to handle stress.