Johns Hopkins group scrutinizes possible biomarker for suicide risk

Researchers at Johns Hopkins are the latest group to take up the quest to find a biomarker that could screen for patients at high risk for suicide.

As The Washington Post and others have reported, they have discovered a possible biomarker, based on a study of approximately 150 brain samples from a mix of deceased patients who had committed suicide, suffered from some sort of mental illness or who had been otherwise mentally healthy. 

They found that the patients who had committed suicide had much higher levels of chemicals called methyls that mutated the SKA2 gene. That's potentially crucial because, as The Washington Post noted, SKA2 is key to governing the brain's response to hormones that cause stress. Details are published in The American Journal of Psychiatry. Researchers from Johns Hopkins University School of Medicine's Department of Psychiatry and Behavioral Sciences and the Department of Mental Health at Johns Hopkins Bloomberg School of Public Health in Baltimore participated in the work.

To buttress their finding, the Johns Hopkins group tested blood samples from more than 325 additional patients to see if the connection between methyls and SKA2 gene mutations in suicidal patients would withstand further scrutiny. According to the article, SKA2 mutations were again connected with suicide risk, giving researchers an accuracy rate of between 80% and 90% in determining whether a person had tried suicide or at least thought about it.

Much more clinical testing is needed to make sure such a test can be viable for routine medical care. Lead researcher Zachary Kaminsky of the Johns Hopkins University School of Medicine cautioned to The Washington Post that the biomarker may indicate tendencies toward anxiety and not necessarily mean a person will pursue suicide.

Still, it is another potential tool that clinicians can use to assess and treat patients. If the researchers' initial thesis stands, a basic blood test could screen for high methyl levels and SKA2 mutations that suggest a patient may be vulnerable to suicide, and those patients could be steered more quickly to the treatments they need.

Other researchers are searching for better diagnostic approaches toward assessing both depression and suicide risks.

Last year, for example, researchers at the Indiana University School of Medicine said they spotted 6 blood-based biomarkers that might help predict suicide, based on a study of blood samples from patients with bipolar disorder and subjects who committed suicide. Additionally, a team from the University of New South Wales in Australia determined last year that greater-than-usual levels of quinolinic acid appear to be a biomarker for severe depression, something that could form the basis of a blood test to screen for high suicide risk.

- read the journal abstract
- here's The Washington Post's take
- consider The Scientist's blog item