To answer your question;
Please understand, I know you didn’t comment out of any malintent. My answer is going to be long, but please don’t take it as an attack. I think that war stress is something that most people are under informed on, and that our media has done us exactly zero favors in that regard, so I’m going to try to answer your question as thoroughly as I can.
Sadly, it is exactly this kind of idea I am trying to combat. The idea that PTSD is somehow ‘new’ or that other cultures (ancient or otherwise) were/are less humanly concerned with violence can be a very damaging opinion. Whether intentional or not, it marginalizes the people now that have the disorder, and makes it seem as though this evolved due to culture, which is an idea that can change, not a biological reaction, which is what it actually is.
I will refer you to another article I wrote which deals exclusively with combat related mental illness.
There are a few things that I think need to be cleared up.
1. Post Traumatic Stress Disorder is not limited to people who have seen combat, and it is not necessarily linked to someone’s mindset, ideas, or preparedness for war. What factors contribute to someone having PTSD have nothing to do with culture, race, age, sex, or ability, or their compunction for killing or not. It has only to do with how much stress that person has been under, and the degree to which that trauma threatened their life or someone they watch get victimized. PTSD appears in combat veterans, victims of natural disasters, victims of domestic and non-domestic criminal violence, child abuse, rape, and small scale accidents like car accidents as well.
(more info: old.impact-kenniscentrum.nl/do… or it is compiled in the other guide I already linked you to)
2. PTSD, which was not originally called that, showed up in the first edition of the Diagnostic and Statistical Manual of Mental Disorders, which was published in 1952. This was the first time that many mental disorders were mentioned and defined. These disorders clearly existed before the printing of the manual, they simply hadn’t been defined and explored. Psychology as a field wasn’t even entertained until around the late 1800s when it began to enter academia and become standardized. Therefore, it was not the disorders that were non-existent, it was the field of study and criteria to evaluate the disorders that were.
3. Not all combat veterans get PTSD. Most come back with some form of mental fatigue or what is called ‘combat stress’, but again, PTSD itself depends on a lot of factors.
As for when and how PTSD showed up in history? Literarily, it is all over both the Iliad and the Odyssey, as well as being explored in the Epic of Gilgamesh, and several Indian literary texts, so it isn’t limited to a single cultural sphere. When I said it shows up in these things, I don’t mean ‘that person went to war then he was sad’ comes up in the text. Actual descriptions of the same exact symptoms, after what are clinically considered ‘traumatic’ events, come up all over the characters in these texts. And PTSD has a very specific set of parameters to even be defined as such, so these are not vague generalizations. Even the more vague examples definitely point to combat fatigue and combat stress, even if the most extreme form of PTSD isn’t realized.
Historically, the same type of situation was noted by a plethora of greek historians, e.g. in Xenophon’s Hellenica (and lots of others), and several Roman writings that related to both soldiers and also non-combat related civilian cases. It has also been studied in 17th century China, and there are several notable examples from Alexander the Great’s army <-- this link may not work, I think you need a login, but if you’re interested I’ve got the article.
The point is, tl;dr, no, it is not modern, and no, it has little to do with anyone’s cultural mindset. Violence and violent death takes its toll, and so does living in a combat condition even if nothing has actually happened to a soldier. Now, is it possible that PTSD was less frequent in some wars than in others? Yes, there is evidence that points to that; it does seem at the moment that soldiers who have more time out of high pressure situations to bury their dead and grieve for them, more time in a zone that is ‘behind the lines’ so to speak, they are less likely to develop PTSD, but no less likely to have some form of lower grade combat stress. And that comes directly from the historical evidence I linked you.
There are cultures, such as the Vikings, that we have much less actual evidence on, save a few writings, and some later third or fourth hand accounts of things, so that is really not enough to go on. But it does seem that human beings are human beings, and while they may not have had cultural compunctions about killing, they had the same psychological sensitivities and stress reactions as anyone else. We have no idea the ratios to which this happened, or how pervasive it was in which settings, but to say it is a modern invention is surely misinformation.