It seems that most soldiers today experience some sort of PTSD. Did soldiers wayyyy back (swords and arrows) experience PTSD? Were they just tougher or did nobody care to write their symptoms down?
This is one of the most often asked questions in this sub, so I recommend taking a look in this section of the FAQ, the VFAQ! It lists the answer of /u/Iphikrates to Did ancient Greek or Roman soldiers ever develop PTSD?, and the answer of /u/hillsonghoods to Monday Methods: on Why 'Did Ancient Warriors Get PTSD' is not such a simple question.