Understanding behavior through the lens of disaster epidemiology

Adverse changes in health behaviors often accompany mass crises, as evidenced by reports of increased substance misuse following terrorist attacks, and more recently, the COVID-19 pandemic. Studying natural disasters provides a window into mechanisms underlying the link between crises and population level changes in health behaviors. By leveraging a natural experiment based on an observation of a natural disaster, my talk will consider alternative theories of behavioral change that follow in the wake of major crises. The Iwanuma Study is a longitudinal study of community-dwelling older adults who were directly impacted by the 2011 Great East Japan Earthquake & Tsunami. The baseline characterization of the cohort, including a comprehensive health assessment, was completed seven months before the disaster. During the decade-long follow-up of survivors, a major health issue that emerged was an increase in incidence of metabolic syndrome (increased body weight, adverse changes in lipids and blood pressure). I discuss competing theories to explain this association, including: (i) changes in the food environment (e.g., local access to fast food outlets) caused by mass residential displacement, (ii) dietary patterns associated with changes in mental health (increased PTSD symptoms, depression), and (iii) heightened present bias associated with asset loss (housing damage) and scarcity.  On top of the acute damage to health and loss of lives, disasters exert a sustained and lingering impact on the health of affected populations through changes in health behavior.