5. When a soldier is in a strange mental state and is rendered unable to fight, but displaying no wounds. Caused by trauma from war experiences or disturbance to the brain by outside forces (artillery shells). http://www.wfa-usa.org/new/shellshock.htm
6.
7. “ What medical officers quickly realized was that everyone had a 'breaking point': weak or strong, courageous or cowardly - war frightened everyone witless. “ - Bourke 'right in the middle of an ordinary conversation' when 'the face of a Boche that I have bayoneted, with its horrible gurgle and grimace, comes sharply into view‘ – An infantry captain