Was it still not known as “shell shock” back then?
Combat fatigue. Do you know the story of Patton slapping his troops who were hospitalized in Italy? It really pissed Ike off and he took Patton out of combat duties.
Conners was supposed to be star ballplayer (basketball and baseball) but according to some of his friends at the time he just didn't seem to be the same guy. Subsequently, it has been accepted he was suffering from PTSD.