You would think that PTSD or other types of after shock would be common when soldiers would kill, club and stab people right in front of them.
Michael Meade's project “Voices of Veterans” uses accounts of Greek soldiers recovering from the horrors of war such as in the tale of Ajax as a therapeutic support for modern soldiers suffering from PTSD. In particular, the modern participants remark how much the ancient descriptions match their modern personal experiences in suffering from war.
You may be interested in the section of our FAQ on Post Traumatic Stress Disorder before the modern era.