The role of moderating factors on the association between exposure to extreme weather-event and mental health and wellbeing in Australia: Findings from an 11-year longitudinal study

Background and Objective Climate-driven extreme weather events (EWE) are increasingly prevalent and severe, posing substantial global challenges to infrastructure and housing. Experiencing flood, bushfire, and cyclone damage to residence can have adverse mental health impacts. In this study, we explore whether the relationship between repeatedly experiencing damage to the home due to EWE and mental health and wellbeing outcomes in an Australian cohort differs by risk and protective factors such as sex, Indigenous origin, and social support. Material and Methods We analysed data from the nationwide longitudinal Household, Income and Labour Dynamics in Australia (HILDA) Survey. Individual exposure was defined as EWE damage to the home in the previous 12 months. Outcomes included mental health and subjective wellbeing (SWB). Risk and protective factors were also examined for effect modification of the association between exposure and outcome. Results Compared with never, one-time exposure to EWE was associated with a 1·5-point decline in mental health (95% CI: -2·65, -0·43) and repeated exposure with a 3·6-point decline in mental health (95% CI: -5·82, -1·40). For SWB, one-time exposure was associated with a 0·1-point decline (95% CI: -0·21, -0·04) compared to those never exposed, while the association with repeated exposure was similar but more uncertain (Adjusted β -0·12, 95% CI: -0·30, 0·05). There was considerable uncertainty regarding effect modification for all moderators tested, with no statistical evidence for any interaction with EWE exposure. However, exploratory stratification did suggest some differences between strata for mental health and SWB outcomes. Conclusion Climate change is expected to raise EWE-related mental health challenges, necessitating urgent interventions and support systems at individual, community, and policy levels. Establishing population susceptibilities and protective factors will be important for building resilience to EWE.