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New Blood-Based PTSD Biomarkers Revealed

by Swathi Kodaikal, MSc | May 31, 2023 | Clinical Diagnostics Insider, Diagnostic Testing and Emerging Technologies, Emerging Tests-dtet

A simple blood test may help screen, identify, intervene, treat, monitor, and eventually, prevent PTSD.

In a new study, researchers at the Walter Reed Army Institute of Research (WRAIR), Silver Spring, MA, and collaborators identified four blood-based biomarkers for post-traumatic stress disorder (PTSD). These biomarkers may help identify, diagnose, and treat individuals with PTSD or those who face a high risk of developing PTSD.¹

What is PTSD?

PTSD is a heterogeneous and severe psychiatric disorder that affects individuals exposed to trauma (e.g., combat, interpersonal violence, and natural disasters).¹ The wide array of symptoms experienced by individuals reflects the heterogeneity of this condition. The most common symptoms include:

Flashbacks

Difficulty sleeping or concentrating

Negative thoughts

Memory problems

Avoidance of triggering situations

Lack of Comprehensive PTSD Indicators

Prior to the advancements in translational research, PTSD was diagnosed based on the intensity of the symptoms and the biological, psychological, and genetic risk factors. Despite extensive research in the past few decades, robust tests that reliably identify PTSD remained unavailable and/or inaccessible. The complexity of PTSD as a condition and the complicated classification system set by The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) add to this issue.²

However, the revised criteria per the DSM-5 include additional symptoms of PTSD that better inform diagnostic criteria.² And the advent of next-generation tools in pathology helped identify PTSD “biomarkers”—molecules in the blood, urine, saliva, and other test samples, which are a measure of physiological changes in biological processes caused by a disease.

In the WRAIR study presented in March at Discover BMB, the annual American Society for Biochemistry and Molecular Biology meeting, the researchers analyzed four biomarkers in the blood samples of participants:³

Glycolytic ratio: a measure of how the body breaks down sugar to produce energy

Arginine: an amino acid that plays a role in the immune and cardiovascular systems

Serotonin: a neurotransmitter that helps regulate mood, sleep, and related functions

Glutamate: a neurotransmitter involved in learning and memory

These biomarkers, alongside a few others, have been previously linked to depression, stress, anxiety, and trauma-related symptoms in individuals.²

Study Findings, Impact, and Applicability

The study was carried out on more than 1,000 active-duty service members. Blood samples were collected before a 10-month deployment period, three days after their return, and three to six months after their return.

The researchers divided the participants into groups based on measures of PTSD—those having PTSD (146), subthreshold PTSD (171), or no PTSD—and resilience. Previous studies showed that individuals with low mental resilience were more likely to develop PTSD when deployed, compared to those with high resilience. So, the researchers classified participants’ resilience based on contributing factors including anxiety, sleep quality, alcohol use disorders, combat exposures, traumatic brain injury, and overall physical and mental health.¹

Upon analysis, researchers found that those in the “having PTSD” and “subthreshold PTSD” categories had significantly higher glycolytic ratios and lower arginine than those with high resilience. Participants with PTSD also had significantly lower serotonin and higher glutamate than those with high resilience. These observations were independent of gender, age, body mass index, smoking habits, and caffeine consumption.¹

Levels of these four biomarkers in the blood may help clinicians identify individuals at a high risk of PTSD, intervene early, and monitor the progress of treatment. However, researchers expressed the need for further research and thorough validation before these biomarkers get introduced to mainstream clinical settings.

What Does the Future Hold?

Cortisol, steroid hormones (estradiol, testosterone, etc.), metabolic hormones (insulin, ghrelin, endocannabinoids, etc.), immune factors (interleukins, tumor necrosis factor, etc.), and several other diagnostic biomarkers have been studied, highlighting the interactions between various organ systems and PTSD. Genetic and psychophysiological factors have also been extensively investigated.^{2, 3}

The complexity and pervasiveness of a condition like PTSD demand a deeper and synergistic analysis of biomarkers and external factors. More in-depth research can only aid better-informed clinical decision-making and, at a larger level, effective policy-making to improve the holistic health of a population.

“Better methods of predicting or screening for PTSD could help to overcome the disorder by identifying individuals at high risk of developing PTSD and providing them with early intervention or prevention strategies,” said Stacy-Ann Miller, MS, a researcher at WRAIR, in a recent press release.³ “This could potentially reduce the severity of symptoms or prevent the disorder from developing altogether.”