What causes psychoneurosis at the front lines? Usually it does not develop in men who have a clear idea of the necessity for the war and understand why they had to get into a GI uniform and do the fighting.
Read this article by Sgt. Mack Morriss
It covers three PDF pages. Read the article here: Page 8, Page 9, Page 10.
Artwork by Cpl. Ruge.
Keep in mind this article was issued to the GI's who did the fighting in 1944. It may not have bearing by modern psychological theories. It may not also take into account the tremendous impact explosives and shelling can have on the human brain. The issue of combat fatigue was very common in WWII. It was misunderstood by many Generals, i.e. General Patton slapping a soldier in a hospital ward trying to snap him out it. By the way, that doesn't work.
Remember to zoom the PDF page to 25% or more for easy viewing.
YANK 31 March 1944