The quest to find viable biomarkers that can help predict suicide risk may have reached a pivotal point, based on a study of blood samples from both bipolar disorder patients and subjects who had committed suicide.
Scientists at the Indiana University School of Medicine said they've spotted 6 blood-based clues they believe could serve as viable predictors of suicide, led by the enzyme SAT1, Popular Science reports. The journal Molecular Psychiatry published the work in detail. If further research backs up the findings, the advance would be a major one for doctors and psychiatrists who struggle to treat bipolar and suicidal patients, as there are no objective markers that can reliably predict suicide risk, principal investigator Alexander Niculescu explained in a statement.
"There are people who will not reveal if they are having suicidal thoughts when you ask them, who then commit it and there is nothing you can do about it. We need better ways to identify, intervene and prevent these tragic cases," said Niculescu, a professor of psychiatry and medical neuroscience at the IU school of Medicine and a researcher at the Richard L. Roudebush Veterans Affairs Medical Center in Indianapolis.
SAT1 and the other potential biomarkers stem from the team's three-year evaluation of a "large group" of patients with bipolar disorder. They tested blood samples on a regular basis, including those from a subset of bipolar patients who began having suicidal thoughts during the course of the study. Once they established that transformation, they explored gene expression changes between patients with lower and higher degrees of suicidal thoughts and then used genetic and genomic analysis to spot potential biomarkers.
Blood samples from suicide victims at the coroner's office helped validate their findings, the researchers noted, when analysis revealed some of the same major biomarkers. And as Popular Science explains, the team pursued further studies of bipolar men and schizophrenic men, and found that the same potential biomarkers helped accurately predict hospitalization for suicide risk (with less accuracy in the schizophrenic patients).
The Popular Science article notes that previous studies identified cerebrospinal fluid as carrying potential suicide biomarkers, but it is difficult and painful to extract. BDNF, a protein involved in neuron growth, has also been eyed in earlier work as a possible option. Earlier this year, a group of Australian researchers said that quinolinic acid could help predict severe depression and high risk of suicide. The substance in small quantities helps repair DNA and produce energy, but higher-than-normal levels can behave like a neurotoxin.
More work is needed to back up the initial findings, but the Indiana researchers are already broadening their scope. They envision moving ahead with a look at other outside factors that might help predict suicide risk, such as clinical and sociodemographic factors.