The first time something like PTSD really popped up in the literature in the modern sense was WW1, in the form of &quot;shell shock&quot; (which was expanded upon as literature and military conflicts evolved). There was this report by a (German?) soldier I remember who explained being in the trenches to being tied to a post, blindfolded, with a man with a massive mallet swinging around and never knowing if or where he's going to it. You feel or hear the mallet striking every time and never know when you're next. 