More may be written of this. You might like to look at an article in the "Post Traumatic Stress Disorder" section of the FAQ: "Was PTSD any more, or any less, prevalent amongst ancient and medieval soldiers than todays soldiers?" by /u/Caherdaniel . Despite the Reddit title, they do discuss the origin of the term "shell-shock" and PTSD. A fuller citation for Winter's article is

Winter, Jay. “Shell-Shock and the Cultural History of the Great War.” Journal of Contemporary History, vol. 35, no. 1, 2000, pp. 7–11. JSTOR, JSTOR, www.jstor.org/stable/261177.

Is that discussion enough? Do you have access to the journal or to JSTOR? I for one would like to know.

This is not to discourage discussion. Further questions, data, and debate are welcome.