The First World War was a breeding ground for psychological trauma. Standing in what were effectively holes in the ground with artillery barrages raining down around them, even the toughest men could break under the strain.
This haunting image was taken in September 1916 at the Battle of Courcelette. The unidentified soldier has lost all perception of reality having retreated in to his own mind hence the maddened smile. Called “Shell shock” at the time, today it would be labelled as Post Traumatic Stress Disorder (PTSD) and while it does gain wider recognition today it is still a major factor affecting forces personnel returning from combat duty.
The man in this image represents a very extreme case although “Shell shock” manifested itself in many ways.
(Image sourced from Historicalphotos.com)