Herodotus and PTSD

In The Golden Mean, I imagine Alexander suffering post-traumatic stress disorder as a result of being trained as a child soldier. Such mental trauma is as old as soldiering; witness this passage from Herodotus describing the aftermath of the Battle of Marathon:

"It happened that an amazing event took place there, when Epizelus son of Cuphagoras, an Athenian who was fighting in the battle and proving himself to be a noble and courageous warrior, was stricken with blindness, though he had not been struck or hit on any part of his body. But from this time on and for the rest of his life, he continued to be blind. I have heard that the story he told about it went something like this: he thought he saw a huge hoplite [heavily-armed foot soldier] whose beard overshadowed his entire shield and who was standing opposite him; but this phantom passed by Epizelus and killed the man standing next to him."

from The Landmark Herodotus: The Histories, Robert B. Strassler, ed., translated by Andrea L. Purvis