The focal point of the book is the soldier's experience on the battlefield that triggers his nervous breakdown - and the author links this up with the soldiers' biographies and provides a perspective on their pre-war civilian life and experience of the war. She then describes the fate of individual soldiers; their psychological and neurological symptoms; their journey through the system of military hospitals and specialist units at home; and the initially ambivalent response of the medical system. She analyses the external factors that influenced clinical presentations of traumatized soldiers and shows how cultural and political factors can shape mental illness and the reactions of doctors and society. The author argues that the challenge posed by tens of thousands of shell-shocked soldiers and the necessity to maintain the fighting strength of the army eventually led to a modernization of medicine - even resulting in the first formal treatment studies in the history of medicine.
"They called it Shell Shock" is also one of the first books to tackle often neglected topics of war history, including desertion, suicide and soldiers' mental illness. Based on her expertise in psychiatry and history of medicine, the author argues that many modern trauma therapies had their root in the medicine of the First World War and that the experience of the shell shock patients and their doctors is still very relevant for the understanding of present-day traumatic diseases.