Shell shock was the signature injury of the First World War. Military doctors during the conflict on the Western Front observed and personally experienced psychiatric states they had never witnessed before. This text reviews the published medical literature of that era which graphically detailed the clinical states of hysteria (conversion disorder) and neurasthenia (anxiety and PTSD). Medical officers at the front evolved pragmatic medicinal, cognitive and behavioural interventions, still practised today, though never scientifically proven to be effective. The doctors, like their patients, endured numerous horrors at the front, which were, for many, to influence their post-war personal and professional lives. Much of what they wrote was forgotten and deserves reconsideration. Neuropsychiatry was founded in the shell craters of Flanders.