when was the term shell shock first used

The term "shell shock" was first used during World War I to describe the psychological trauma experienced by soldiers exposed to the extreme stress of combat, particularly from the constant bombardment of artillery shells. It became increasingly recognized as a legitimate medical condition during the war, though its understanding and treatment were still in their early stages. Over time, the terminology evolved, and in subsequent conflicts, such as World War II, the term "combat stress reaction" or "battle fatigue" came into use to describe similar conditions. Today, it is understood as a form of post-traumatic stress disorder (PTSD).