AbstractAlthough there is a wide-ranging historiography dealing with psychoneurosis, various manifestations of psychic suffering widespread among traumatised soldiers during the Great War have received less attention. This essay, based on an analysis of soldiers' clinical files in Italian psychiatric hospitals, draws out these phenomena. The main forms assumed by this kind of trauma are three: soldiers who strip off their uniform and wander around naked; a sort of regression to childhood; and a particular type of hysteria. The essay stresses how existingstereotypes about women were adapted to form a new way of describing masculinity in crisis, and the new political subject: the masses. Too many emotions, too many nerves, define the affected men: they are subjects deprived of personality, and their predicament highlights the transition from soldier-hero to mass-soldier.