Experimental induction of psychogenic illness in the context of a medical event and media exposure.

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.

RCT Entities:   Population Interventions Outcomes