A new study published in Nature Health warns of a likely increase in hospitalizations for mental health and behavioral disorders following the recent July 4 heatwave in the United States, according to a Jul. 10 report. The research, led by Professors Yuming Guo and Shanshan Li from Monash University in Australia, is described as the first multi-country analysis of heatwave-related mental health hospitalizations.
The study examined over 2.6 million warm-season hospital admissions between 2000 and 2019 across 852 locations in Brazil, Canada, Chile, and New Zealand. Researchers found that sustained exposure to extreme heat during heatwaves was associated with an increased risk of hospitalization for mental and behavioral disorders.
A heatwave is defined as a period of extremely high ambient temperatures lasting several days, during which rates of heat-related illness and death rise significantly. Professor Guo said the link between exposure to a heatwave and hospitalization for mental or behavioral disorders was stronger among older adults and people living in low-population-density areas.
Professor Li said climate change "has emerged as a pressing factor influencing mental health on a global scale, with extreme weather events, resource scarcity and ecosystem disruptions amplifying psychological stress and mental health risks." She added that "one noticeable climate-related issue is the increasing frequency and intensity of heatwaves, such as those being experienced in the US and across Europe at the moment."
Researchers suggested that acute exacerbations of mental or behavioral disorders may be triggered by sleep disruption or physiological stress responses during periods of intense heat. Individuals with impaired thermoregulation or medication-related sensitivity to high temperatures are considered especially vulnerable. Heat-induced psychological distress or behavioral changes may also contribute to destabilization of symptoms leading to higher rates of hospital admission.
This research is noted as the first effort to estimate risks associated with heatwave-related hospitalization for mental health conditions across different countries, demographic groups, economic backgrounds, population densities, air-conditioner use levels, travel times to healthcare facilities, and specific causes behind psychiatric admissions.
