# Tropical Cyclone Exposure and Psychoactive Drug–Related Death Rates

## TL;DR

Tropical cyclone exposure in US counties is linked to increased psychoactive drug-related deaths in the months following the event.

## Contribution

This study is the first national multidecadal analysis linking cyclone exposure to drug-related death rates, stratified by cyclone strength and demographic factors.

## Key findings

- Each additional cyclone-exposed day was associated with a 3.84% increase in psychoactive drug-related death rates in the month of exposure.
- Increases in death rates persisted up to 3 months after cyclone exposure.
- Younger adults (15-44 years) showed higher increases in death rates compared to older adults.

## Abstract

In the US during 1988 to 2019, was county-level tropical cyclone exposure associated with increases in county-level psychoactive drug–related death rates in subsequent months?

In this case-control study of 798 691 psychoactive drug–related deaths in 1258 counties that experienced tropical cyclones from 1988 to 2019, each additional cyclone-exposed day per month was associated with a 3.84% increase in death rates in the month of cyclone exposure and a 3.76% increase in the month after.

Among US counties exposed to tropical cyclones from 1988 to 2019, each additional cyclone-exposed day per month was associated with an increase in psychoactive drug–related death rates in the months following exposure.

This case-control study examines whether county-level tropical cyclone exposure is associated with changes in psychoactive drug–related death rates in the US.

Tropical cyclone exposure exacerbates substance use and mental and behavioral health vulnerabilities in affected communities, potentially contributing to increases in psychoactive drug–related deaths (including drug overdoses, alcohol-related deaths, and other substance-related disorders). Prior research has not evaluated this association in a national multidecadal study by cyclone strength and demographic subgroup.

To estimate the association between county-level tropical cyclone exposure and psychoactive drug–related death rates in the US.

This case-control study used a bayesian conditional quasi-Poisson model to evaluate the association between county-level tropical cyclone exposure and monthly psychoactive drug–related death rates between January 1, 1988, and December 31, 2019. Participants included residents of counties in the contiguous US that were exposed to at least 1 tropical cyclone during the study period. Death data were obtained from the National Center for Health Statistics. Analyses were conducted between March 27, 2024, and June 25, 2025.

Monthly tropical cyclone–exposed days per county, defined by sustained wind speeds of at least 34 knots, categorized as gale to violent storms (34-63 knots) and hurricanes (≥64 knots).

The main outcome was monthly county-level psychoactive drug–related death rates. Associations were estimated between each additional cyclone-exposed day and death rates in the subsequent 0 to 3 months. Analyses were stratified by cyclone strength, age, sex, and county-level social disadvantage (poverty level and percentage of racial and ethnic minority residents).

Among 1258 exposed counties between 1988 and 2019, 798 691 psychoactive drug–related deaths were recorded (29.5% females and 70.5% males; 99.8% aged ≥15 years). Median exposure was 2 tropical cyclone days (range, 1-27 days) during the study. Each additional cyclone-exposed day was associated with a 3.84% increase (95% bayesian credible interval [CrI], 1.83%-5.89%) in psychoactive drug–related death rates in the month of exposure, persisting up to 3 months after exposure (2.39% [CrI, 0.41%-4.40%]). Older children and younger adults (15-44 years old) demonstrated statistically higher increases than older adults after exposure. However, increases were limited to low-poverty counties regardless of racial composition (13.05% [CrI, 6.79%-19.68%] for low presence of racial and ethnic minority residents; 6.01% [CrI, 3.02%-9.08%] for high presence) in the month of tropical cyclone exposure.

In this case-control study of US counties, tropical cyclone exposure was associated with increased psychoactive drug–related death rates up to 3 months after exposure. These findings support the integration of substance use and mental health services into climate disaster preparedness and response planning.