Indiana University School of Medicine researchers have identified a number of blood-based genetic markets of psychological stress, which could lead to better diagnostics for post-traumatic stress disorder (PTSD), and bring forward new drug development leads.

PTSD and other stress disorders are, the researchers said, “prevalent, disabling, and under-diagnosed in both the military and civilian realm”. PTSD occurs as mental and physical over-reaction to environmental cues, and which are provoked by past exposure to traumatic events. They are often undiagnosed, and can lead to violence or suicide in severe cases.

The study, published in Molecular Psychiatry and which took ten years to complete, analysed 250 veterans for biomarkers linked to the severity of their stress and possibility of future hospitalisations. Three cohorts of patients were included in the test: first, researchers broadly searched for changes in gene expression between one cohort of participants’ self-reported low- and high-stress states, before prioritising a list of candidate markers, comparing and analysing the initial findings against existing studies of gene expression in psychiatric disorders.

Following that, the top biomarkers were validated against the second cohort of patients, before being tested for their ability to predict high-stress state and future psychiatric hospitalisations with stress in the third cohort.

The study found 285 individual biomarkers associated with 269 genes. Some of the newly-detected biomarkers, including NUB1 and APOL3, were found to be even more effective at predicting states of stress than telomere length in biomarkers or a well-recognised biomarker involved in stress response, FKBP5.

According to the scientists, more than half the top predictive biomarkers for stress also had prior evidence of involvement in suicide: “and the majority of them had evidence in other psychiatric disorders, providing a molecular underpinning for the effects of stress in those disorders.

“We think that one of the key uses of our research would be to test people before they have symptoms of an illness to see who’s at risk and possibly treat them early.”