Researchers reviewed existing studies to look for biological markers that might predict which children and adolescents will develop persistent PTSD after experiencing trauma. They analyzed 21 studies involving young people who had been exposed to traumatic events, searching for patterns in biological measurements taken after the trauma.
The main finding was relatively consistent evidence that children with a higher heart rate measured soon after a trauma had an increased risk of their PTSD symptoms persisting over time. The evidence for other potential biological markers was much more limited. No safety concerns were reported, as this was a review of observational studies, not a treatment trial.
It is important to be careful with these results for several reasons. The studies varied greatly in the types of trauma, how children were selected, and how heart rate was measured. The overall number of studies was small, and there were methodological issues that limit what we can conclude. There was also a notable lack of research from low- and middle-income countries. Readers should understand that this shows a link, not a cause, and that a child's heart rate after trauma is just one piece of a very complex picture.