Post-traumatic stress disorder was a major military problem during World War I, though it was known at the time as “shell shock.” The term itself first appeared in the medical journal The Lancet in Feb. 1915, some six months after the “Great War” began.

When and how did it come into use shell shock?

By the winter of 1914–15, "shell shock" had become a pressing medical and military problem. Not only did it affect increasing numbers of frontline troops serving in World War I, British Army doctors were struggling to understand and treat the disorder. The term "shell shock" was coined by the soldiers themselves.

How long did shell shock last?

Evolution away from shell-shock

Work from other clinicians after WWII and the Korean War suggested that post-war symptoms could be lasting. Longitudinal studies showed that symptoms could persist anywhere from six to 20 years, if they disappeared at all.