Wildfires, brain health and mental health: A narrative review on the physiological and psychological interplay.

As climate change intensifies, the frequency and severity of wildfires are increasing, with accumulating evidence of significant impacts on human health. However, the physiological and psychological impacts of wildfire exposure are often examined separately, obscuring their interconnected nature. This narrative review integrates these perspectives to examine how wildfires affect brain and mental health and to highlight the interplay between mind, brain, body, and environment. We first review epidemiological and experimental evidence demonstrating physiological effects of wildfire smoke on brain health, including neurodegeneration and cognitive impairment, cerebrovascular effects, neurodevelopmental disruptions, and mental health outcomes. Wildfire smoke is of particular concern due to its ability to travel long distances, persist in the atmosphere, and its distinct physiochemical profile, for which accumulating evidence indicates greater toxicity than particulate matter from other pollution sources. Across studies, neuroinflammation and oxidative stress emerge as key physiological pathways linking wildfire smoke to adverse brain outcomes. We then examine how wildfire events affect mental health, applying a socio-ecological framework to outline psychological pathways from individual characteristics to broader surrounding environmental contexts. Thereafter, we discuss the interplay between physiological and psychological outcomes of wildfire experiences within the framework of an interconnected mind, body, brain and environment. Existing evidence for interactions between these systems is synthesised, highlighting research within a wildfire context. Finally, we outline future research priorities and public health implications. We highlight the need for mechanistic experimental research with standardised protocols, expanded epidemiological studies leveraging new technologies, and evaluations of interventions to inform evidence-based policy. We emphasise that supporting populations exposed to wildfires will require holistic, systems-based approaches that recognise the interdependence of physiological and psychological processes.