PTSD is a condition that has been commented on throughout history, but just given different names. Although I don't study it professionally, I'm a combat veteran who was diagnosed with PTSD in 2010, and I ended up doing some research on my own just out of sheer curiosity.
There are a few areas of study that I might recommend investigating for further guidance. This is a website that was recommended to me a few year ago by my doctor and it explains the history of PTSD starting around the year 1,000 B.C.E. in Ancient Egypt. https://www.myptsd.com/c/articles/history-of-posttraumatic-stress-disorder.9/
For more contemporary sources, there is a superb documentary that was produced by HBO called War Torn: 1861-2010 and it follows the history of PTSD from the American Civil War through every major combat narrative until 2010. It's well done and well sourced.
Hope this helped.
Rather recently, people have turned to Sophocles' "Ajax" and "Philoctetes" for looking at the psychological ramifications of pain and war
You may have already seen this article or performance, but it was quite interesting: http://www.nytimes.com/2009/11/12/theater/12greeks.html?pagewanted=all&_r=0