I think it's interesting to note that in WW1 PTSD like symptoms were called shell-shock, and were believed to be a consequence of exposing the human body to artillery fire. Compare that to this quote from the article:
he was grappling with sleeplessness, depression and severe memory problems.
“A lot of us are like that,” he said. “It’s not psychological — there is something physiologically wrong. And a lot of guys struggle.”