Battle fatigue

combat fatigue, traumatic condition suffered by soldiers who have been in combat

Combat stress reaction, in the past commonly known as shell shock or battle fatigue, is a military term used to categorize a range of behaviours resulting from the stress of battle which decrease the combatant's fighting efficiency. The most common symptoms are fatigue, slower reaction times, indecision, disconnection from one's surroundings, and inability to prioritize. Combat stress reaction is generally short-term and should not be confused with acute stress disorder, post-traumatic stress disorder, or other long-term disorders attributable to combat stress although any of these may commence as a combat stress reaction.
See more at Wikipedia.org...

Bat·tle fatigue or bat·tle neurosis n. See combat fatigue. battle fatigue Posttraumatic stress disorder, see there [more]Battle fatigue - Community and Resources

Noun
1. a mental disorder caused by stress of active warfare
(synonym) combat fatigue, combat neurosis, shell shock
(hypernym) posttraumatic stress disorder, PTSD

The World War II name for what is known today as post-traumatic stress, this is a psychological disorder that develops in some individuals who have had major traumatic experiences (and, for example, have been in a serious accident or through a war). The person is typically numb at first but later has symptoms including depression, excessive irritability, guilt (for having survived while others died), recurrent nightmares, flashbacks to the traumatic scene, and overreactions to sudden noises. Post-traumatic stress became known as such in the 70s due to the adjustment problems of some Vietnam veterans.