Investigators have identified potential serum biomarkers to flag patients at high risk of suicide. The research determined that patients with major depressive disorder (MDD), who died by suicide, had a signature gene expression compared to patients who died by other means.

The findings published in Translational Psychiatry reported that the identified signature gene was involved in stress response change, including polyamine metabolism, circadian rhythm immune dysregulation, and telomere maintenance.

Adolfo Sequeira, Ph.D., University of California Irvine School of Medicine added that the biomarkers are a crucial step toward developing a blood test to identify patients with imminent risk of suicide. The first study to analyze the blood and the brain samples showed a significant difference in gene expression.

Over the past 2 decades, suicide rates have jumped by 35% in the US with 48000+ deaths occurring by suicide in the past year. MDD is the most common diagnosis among suicide cases and remains a pressing challenge for researchers. The findings of the study are archived as post-mortem blood and brain samples from adults who died by suicide (MDD-S) and by other means (MDD-NS). The total number of blood and brain samples were 53 and 69 respectively, from 45 adults. From the samples, 14 genes were isolated out of which 6 genes differentially expressed in the blood samples were PER3, MTPAP, SLC25A26, CD19, SOX9, and GAR1. However, out of these 6 genes, SOX9, PER3, and CD19 showed significant changes in the samples collected from MDD-S and MDD-NS suggesting similar immune dysregulation in suicide that could further be investigated.

Two nuclear gene coding for mitochondrial proteins namely MTPAP and SLC25A26 were also observed to have increased in the blood samples of the MDD-S group suggesting mitochondrial alteration could also be used as a potential factor to differentiate between the two groups.

She also added that these genes also represent a potential target for future drug therapies to prevent suicide along with the technological development of a specific and effective molecular test to identify individuals at high risk for suicide.