Heart rate variability appears to be a physiological predictor of PTSD symptoms in veterans, according to research published in the journal Biological Psychology.

The study measured hundreds of Army National Guard soldiers’ heart rate variability — meaning the variation in the time interval between heartbeats — before they were scheduled to deploy to Iraq in 2011. The researchers found an inverse relationship between pre-deployment HRV and PTSD symptom severity after deployment.

PsyPost interviewed the study’s corresponding author, Jeffrey M. Pyne of the University of Arkansas for Medical Sciences. Read his responses below:

PsyPost: Why were you interested in this topic?

Pyne: I first became interested in this topic during my involvement with a study of prolonged exposure therapy for post-traumatic stress disorder (PTSD) augmented by virtual reality and heart rate variability (HRV) monitoring in active duty Marines and Navy personnel. I was not conducting the therapy but it was clear that HRV was inversely related to distress during the therapy sessions.

At the time, most studies in this area were demonstrating an inverse relationship between HRV and PTSD symptom severity. I was a psychiatrist in the Navy Reserves recalled to active duty and we were deploying large numbers of military personnel to Iraq and Afghanistan. I wondered if HRV could also be used as an objective and potentially modifiable pre-deployment predictor of post-deployment PTSD.

What should the average person take away from your study?

Pre-deployment HRV is an objective and potentially modifiable risk factor that predicted post-deployment PTSD symptom severity.

Are there any major caveats? What questions still need to be addressed?

There are major caveats. One is that pre-deployment HRV was only a significant predictor in soldiers who had higher pre-deployment PTSD symptoms. However, the level of pre-deployment PTSD symptoms severity where HRV was a significant predictor was below any cut-off score that is used to clinically identify risk for PTSD.

Questions that still need to be addressed include: (1) our results need to be replicated, (2) are there HRV interventions that can decrease risk, (3) there were soldiers with low pre-deployment HRV who did not have elevated post-deployment PTSD symptoms – why not?

Is there anything else you would like to add?

HRV monitoring is now becoming commercialized and as such may provide additional opportunities to utilize this objective measure of health in other at-risk populations.

The study was titled: “Heart rate variability: Pre-deployment predictor of post-deployment PTSD symptoms“.