Could a blood test predict suicide risk?

World Health Matters by Gary Finnegan – United States – A series of RNA biomarkers have been found which researchers say could help to identify people at risk of committing suicide.

In a paper published in Molecular Psychiatry, scientists at the Indiana University School of Medicine said the biomarkers were found at significantly higher levels in the blood of bipolar disorder patients with thoughts of suicide, as well in a group of people who had committed suicide.

Principal investigator Dr Alexander B. Niculescu, associate professor of psychiatry and medical neuroscience at the IU School of Medicine, said he believes the results provide a first “proof of principle” for a test that could provide an early warning of somebody being at higher risk for an impulsive suicidal act.

“Suicide is a big problem in psychiatry. It’s a big problem in the civilian realm, it’s a big problem in the military realm and there are no objective markers,” said he said. “There are people who will not reveal they are having suicidal thoughts when you ask them, who then commit it and there’s nothing you can do about it. We need better ways to identify, intervene and prevent these tragic cases.”

Over a three-year period, Niculescu and his colleagues followed a large group of patients diagnosed with bipolar disorder, completing interviews and taking blood samples every three to six months.

The researchers conducted a variety of analyses of the blood of a subset of participants who reported a dramatic shift from no suicidal thoughts to strong suicidal ideation. They identified differences in gene expression between the “low” and “high” states of suicidal thoughts and subjected those findings to a system of genetic and genomic analysis called Convergent Functional Genomics that identified and prioritised the best markers by cross-validation with other lines of evidence.

The researchers found that the marker SAT1 and a series of other markers provided the strongest biological “signal” associated with suicidal thoughts.

Next, to validate their findings, working with the local coroner’s office, they analysed blood samples from suicide victims and found that some of same top markers were significantly elevated.

Finally, the researchers analysed blood test results from two additional groups of patients and found that high blood levels of the biomarkers were correlated with future suicide-related hospitalisations, as well as hospitalisations that had occurred before the blood tests.

“This suggests that these markers reflect more than just a current state of high risk, but could be trait markers that correlate with long-term risk,” said Dr. Niculescu.