Shell shock
In World War I, many soldiers had psychological problems. These kinds of problems are known as post-traumatic stress disorder (or PTSD) today. The term post-traumatic stress disorder is relatively new. At the time, people such as Charles Samuel Myers called this condition shell shock.   Shell shock is a reaction to bombardment and fighting. Soldiers who were affected often felt helpless. Very often they panicked, were scared, and tried to flee. They were also unable to reason, sleep, walk or talk.