The history of the diagnostic term post-traumatic stress disorder (PTSD) weaves back to the diagnoses of “shell shock” during World War I, and even earlier to the Napoleonic Wars and the American Civil War.

Dr. Charles Samuel Myers, a consulting psychologist and physician to the British Army during World War I, first coined the term “shell shock” to describe the neurobehavioral difficulties—including emotional and cognitive breakdown and problems with balance—that military physicians observed in soldiers incapacitated due to combat exposure. It is estimated that 80,000 British soldiers suffered from shell shock, and 100,000 German soldiers were treated for what was termed “hysteria” in military field hospitals during World War I.

Read more at Psychology Today.