Post traumatic stress is a big issues for combat veterans today, and as far as I've seen has been a prevalent issues since identified as "shell shock" in WWI and likely before. In the media this is shown as well, but as far as I have seen it is not shown in warrior cultures such as the vikings or Greeks. So, are there recorded instances of PTS in early history? And if not, could it be attributed to these cultures spiritual beliefs about warriors?
You may find these previous long-form answers useful:
Post Traumatic Stress Disorder in the FAQ by various contributors
Did ancient civilians get PTSD? What do we know of the psychological effects of war on noncombatants, and how they dealt with them? also by /u/Iphikrates
Monday Methods: On why 'Did Ancient Warriors Get PTSD?' isn't such a simple question. by /u/hillsonghoods