5G-05 - The impact of extreme heat on mental health utilization and prescription use

Background: Existing research has highlighted the link between temperature and physical health, but the relationship between heat and mental health remains underexplored.

Objectives: This study investigated the impact of temperature, particularly extreme heat on mental health care utilization and costs related to schizophrenia; mood disorders including depression; and anxiety, dissociative, stress-related, and other nonpsychotic mental disorders across diverse service settings. Additionally, we examined prescription fills and costs for antianxiety, antidepressant, and antipsychotic medications.

Methods: We used claims from 2016-2023 from a U.S. payor covering approximately 35 million individuals with commercial, Medicare Advantage or Medicaid plans. We aggregated daily-level claims to the Census tract-week level. We estimated the effect of the daily heat index (HI) on contemporaneous mental health emergency department (ED), inpatient, outpatient, and telehealth utilization and commonly prescribed mental health prescription fills using Poisson regressions. We estimated percent change in utilization using tract-week, tract-year, and cumulative week fixed effects to allow for the comparison of unseasonably hot or cold weeks for a tract, while accounting for broader economic and temporal factors.

Results: Mental health care utilization and prescription fills were more sensitive to extreme heat than general health care use. Mental health-related visits across places of service were 1.42% (CI: 0.62%-2.23%) higher and all-cause visits were 0.82% (CI: 0.70%-0.93%) higher on days with a heat index temperature above 100F heat index as compared to 60-70F. This effect compounded with additional hot days: a week with temperatures consistently all days above 100F heat index would see nearly a 10% rise in all-cause visits as compared to a more temperate week.
The analysis of prescription data revealed complex associations. We observed decreases in fills for anxiolytics (-0.4%, CI:-0.47%- -0.33%) and antidepressants (-0.19%, CI:-0.24%- -0.14%) during unseasonably cold days below 30F compared with more temperate days between 60-70F. Unseasonably hot days over 100F HI were associated with a 0.21% (CI: 0.11%-0.32%) increase in fills of antipsychotic medications.

Conclusions: Our study suggests that temperature extremes, especially heat, may exacerbate mental health conditions, driving an increase in utilization and prescription fills. Extreme cold may hinder access to psychotropic medications. These findings underscore the need for adaptive strategies in mental health services to address climate-related risks.