Researchers at the Indiana University School of Medicine report they have found a series of RNA biomarkers in blood that may help identify who is at risk for committing suicide.
The biomarkers were found at significantly higher levels in the blood of both bipolar disorder patients with thoughts of suicide, as well in a group of people who had committed suicide, according to the researchers.
The results provide a first “proof of principle” for a test that could provide an early warning of someone with a higher risk for an impulsive suicide act, according to the study’s principal investigator, Alexander B. Niculescu III, M.D., Ph.D., an associate professor of psychiatry and medical neuroscience.
“Suicide is a big problem in psychiatry,” he said.
“It’s a big problem in the civilian realm, it’s a big problem in the military realm and there are no objective markers. 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.”
The researchers followed a group of patients diagnosed with bipolar disorder over a three-year period, conducting interviews and taking blood samples every three to six months.
They then 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 thoughts.
They identified differences in gene expression between the “low” and “high” states of suicidal thoughts. Those findings were then subjected to a system of genetic and genomic analysis called Convergent Functional Genomics that identified and prioritized the best markers by cross-validation with other lines of evidence, the researchers explained.
What they found is that the marker SAT1 and a series of other markers provided the strongest biological “signal” associated with suicidal thoughts, they report in the study, which was published in the online edition of the journal Molecular Psychiatry.
To validate their findings, the researchers analyzed blood samples from suicide victims. They reported that some of same top markers were “significantly” elevated.
Finally, the researchers analyzed blood test results from two additional groups of patients and found that high levels of the biomarkers correlated with future suicide-related hospitalizations, as well as hospitalizations 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 Niculescu.
Although confident in the validity of the biomarkers, Niculescu noted that a limitation of the study is that all of the research subjects were male.
“There could be gender differences,” he said. “We would also like to conduct more extensive, normative studies, in the population at large.”
In addition to extending the research to females, Niculescu said he and his colleagues plan to conduct research among other groups, such as people who have less impulsive, more deliberate and planned types of suicide.
Even so, Niculescu noted that the the markers seem to be good for “suicidal behavior in males who have bipolar mood disorders or males in the general population who commit impulsive violent suicide.”
He noted that the researchers want to “study and assemble clinical and socio-demographic risk factors, along with our blood tests, to increase our ability to predict risk.”
“Suicide is complex: In addition to psychiatric and addiction issues that make people more vulnerable, there are existential issues related to lack of satisfaction with one’s life, lack of hope for the future, not feeling needed, and cultural factors that make suicide seem like an option,” he continued.
He added he hopes the biomarkers, along with other tools, including neuropsychological tests and socio-demographic checklists currently in development by his group, can one day help identify people who are at risk, leading to pre-emptive intervention, counseling, and saved lives.
“Over a million people each year worldwide die from suicide and this is a preventable tragedy,” he concluded.
Source: Indiana University