25% sounds a big number when you start to think about it.
What about all the policemen, firemen, paramedics and doctors that have to deal with death and danger to their own life during their careers?
Many times involving small children as victims, something that i personally find moving.
My personal experiences from something possibly traumatising are being shot above my head and pointed in the face with a gun and nearly escaping from being crushed under a truck.
Ive never had any stressing toughts on neither incident.
I read once that there are strong indicators of genetic and childhood factors that mainly contribute to getting a stress disorder.
If so i wouldnt rule out the possibility to create tests for screening these beforehand.