Objectives Mass psychogenic illness can be a significant problem for triage and hospital surge in disasters; however, research has been largely limited to posthoc observational reports. Reports on the impact of public media during a disaster have suggested both salutary as well as iatrogenic psychological effects. This study was designed to determine if psychogenic illness can be evoked and if media will exacerbate it in a plausible, controlled experiment among healthy community adults. Methods A randomized controlled experiment used a simulated biological threat and elements of social contagion—essential precipitants of mass psychogenic illness. Participants were randomly assigned to one of three groups: no-intervention control group, psychogenic illness induction group, or psychogenic illness induction plus media group. Measures included three assessments of symptom intensity, heart rate, blood pressure, as well as questionnaires to measure potential psychogenic illness risk factors. Results The two psychogenic induction groups experienced 11 times more symptoms than the control group. Psychogenic illness was observed in both men and women at rates that were not significantly different. Higher rates of lifetime history of traumatic events and depression were associated with greater induction of illness. Media was not found to exacerbate symptom onset. Conclusions Psychogenic illness relevant to public health disasters can be evoked in an experimental setting. This sets the stage for further research on psychogenic illness and strategies for mitigation.

Psychogenic illness during disasters can cripple emergency healthcare services. Almost all research into this phenomenon has been retrospective and observational, and much of it suggests that media coverage can amplify psychogenic outbreaks. But there is little empirical evidence that this is true or that, conversely, media reports can mitigate psychogenic symptoms. In their work experimentally inducing psychogenic illness, the authors became sharply aware that it is difficult to experimentally mimic real-time media coverage. Yet clarifying media’s effects on psychogenic illness is important if we want to prevent psychological disturbance. To meet this challenge, the authors advocate the funding and development of research protocols in advance of public emergencies, ready to be implemented in real-time. Coupled with digital media, which can track the reading and viewing behavior of millions of people, this approach can help us better understand media’s impact on public health during an emergency, for better or for worse.