[en-us]

To add to this, there is a book called The Body Keeps the Score that dedicates several of its chapters to exploring the physiological consequences of trauma. Some of the changes are quite profound and I have a hard time believing that just one or two hundred years of evolution would have an appreciable effect in this matter. We can't teleport a combat veteran from antiquity into an fMRI but either the findings would be the same or something very profound changed in the human brain in a very short period of time and it went unnoticed.

I think it is far more likely that people either didn't discuss these things due to stigma, or they conceptualized it as the haunting of demons and ghosts since severe cases of PTSD can cause split personalities and convulsions and things like that.