Extreme Weather Events and Mental Health Services Use Among Working-Age Adults

Evidence on the long-run mental health effects of disasters remains limited. This study estimates the causal effects of exposure to extreme weather events (EWEs) on mental health treatment among working-age adults in New Zealand. Unlike much of the existing literature, which focuses on single disasters, short-term outcomes, and self-reported distress, we use longitudinal administrative population data within a staggered difference-in-differences framework to exploit variation in the timing and frequency of exposure across individuals and regions. The analysis distinguishes between moderate and severe mental health conditions and estimates effects on both the probability of receiving treatment and the number of treatment days. We find no statistically significant population-level effects of EWE exposure on treatment of either moderate or severe mental illness. However, subgroup analyses indicate some heterogeneity, particularly among individuals in the lowest income tercile and younger adults for moderate outcomes. Overall, the findings suggest that increases in psychological distress documented in the broader disaster literature do not necessarily translate into broad-based or sustained changes in formal mental health treatment. The study provides new evidence on how climate-related shocks shape realised mental healthcare utilisation over time.