摘要:I explore the hypothesis that Hurricane Katrina in August 2005 raised perceived background risks, which had spillover effects on behavioral health outcomes of mental health and substance use. I estimate the effect that Katrina had in the nondamaged storm surge region, in time intervals leading up to and after the hurricane, compared to areas impervious to hurricanes. I find causal evidence that Katrina increased poor mental health days by 18.8% for the first month after Katrina, and increased smoking among lifetime smokers until 2007. Effects were larger in counties with disproportionate risk to storm surge and for low‐educated individuals. (JEL D81, I12, Q54)