The association between environmental quality and mental health using electronic health records in North Carolina

Depression and anxiety are common disorders that contribute to diminished quality of life, worse cardiovascular outcomes, and high suicide rates in United States (US) adults. Poor mental health arises from complex factors including genetics, psychology, and lived experiences. Increasingly, environmental exposures are thought to impact mental health. We used electronic health records from a random sample of 14,685 adult (≥18 years old) patients seen at University of North Carolina-affiliated hospitals across the state’s 100 counties, from 2006 to 2018. We linked those geocoded data to the US Environmental Protection Agency’s 2006-2010 county-level environmental quality index (EQI), consisting of 5 unique domain indices (air, water, land, built, and sociodemographic) and an overall EQI for the US. We used log-binomial regression to estimate the association between North Carolina-specific tertiles of environmental quality (domain-specific and overall EQI) and diagnosis of a major depressive episode or generalized anxiety disorder (ICD-9 296.2, 296.3, 300.2; ICD-10 F32, F33, F42.1), controlling for sex, age, and race. Resulting prevalence ratios (PR) and 95% confidence intervals (CI) compared worst to best (referent) tertile of environmental quality. Residents of counties with the worst air and built environments were more likely to have anxiety or depression (PR 1.46; 95% CI 1.30, 1.64 and PR 1.17; 95% CI 1.06, 1.28, respectively). We observed inverse associations between anxiety or depression and land (PR 0.65; 95% CI 0.58, 0.73), sociodemographic (PR 0.59; 95% CI 0.48, 0.71), and water (PR 0.83, 95% CI 0.75, 0.91) domains. Associations with the overall EQI and anxiety or depression diagnoses were null (PR 1.01; 95% CI 0.92, 1.11). Our results suggest variation in how different domains of environmental quality may impact mental health disorders; worse air quality and built environment disamenities may be especially harmful. This abstract does not reflect EPA policy.

Impact/Purpose

Anxiety and depression are common disorders that can diminish quality of life for those affected. Environmental exposures are increasingly believed to impact mental health. We examined associations between county-level environmental quality index, overall and by five domains (air, built, land, sociodemographic, and water) with anxiety or depression among 14,685 adult patients seen at University of North Carolina-affiliated hospitals from 2006 to 2018. Residents of counties with the worst air and built environments were more likely to have anxiety or depression. Residents of counties with the worst land, sociodemographic, and water environments were less likely to have anxiety or depression. We did not observe associations with the overall EQI and anxiety or depression diagnoses. Associations between environmental quality and mental health may differ by domain of environmental quality.

Citation

Gray, C., A. Weaver, C. Ward-Caviness, J. Moyer, K. Rappazzo, L. Messer, J. Jagai, A. Krajewski, M. Jimenez, AND D. Lobdell. The association between environmental quality and mental health using electronic health records in North Carolina. Society for Epidemiologic Research, San Diego, CA, June 22 - 25, 2021.