I only personally knew of two people who went through enough of war to have PTSD. One was a woman who was a survivor of one of the death camps. She was liberated before it was her turn for the Zyklon-B. The other was my (late) father-in-law who went ashore at Omaha Beach on D-Day, 3rd wave. His unit went north-east and eventually liberated more than one death camp. Until his dying day about 10 years ago, he never opened up about it any more than to get a far-away look and talk about how disgusted he was that people could treat other people in such a horrible way. Both of these people had dealt with their stress to the point of being functional in society again, but neither one ever lost that haunted look.