With temperatures soaring across the country, many of us are bracing ourselves for the worst – but there's another, often overlooked consequence of extreme heat: our mental health. Research from the University of Sydney has revealed a disturbing link between scorching summers and an increased risk of young people being hospitalised with mental health conditions.
The study, which analysed over 720,000 hospital admissions in New South Wales, Australia, found that during warmer months, the risk of such admissions doubled when daily average temperatures were among the highest 1% for that specific day. This risk was observed to triple during cooler months under similar extreme temperature conditions.
Published in the Journal of the American Academy of Child and Adolescent Psychiatry, the research examined admissions for a wide range of mental health disorders, including schizophrenia, depression, substance misuse, eating disorders, and self-harm, between 2001 and 2022. The lead author, Dr Wen-Qiang He, noted the significant increase in admissions for younger populations as temperatures rise, underscoring the importance of this finding for community awareness and preparedness.
The study projects that as global heating leads to more frequent extreme temperatures, heat-related hospital admissions could increase by 6% to 7.7% by the end of the century. While the research did not explicitly determine the mechanisms behind this correlation, authors suggest several potential causes. These include direct impacts of higher absolute temperatures on brain function in warmer months, and how unexpected temperature changes, even in winter, can affect stress management, sleep patterns, and mood.
Dr Cybele Dey, an adolescent psychiatrist and co-author, pointed to the minimal lag between temperature spikes and hospital admissions, suggesting a direct 'physiological' response to heat. She emphasised that these are not minor presentations, as hospital admission indicates a serious level of distress. Dr Hasini Gunasiri, a research fellow at Orygen, a youth mental health research institute, who was not involved in the study, highlighted practical implications, suggesting young people might use substances to cope with discomfort or sleep disruption during extreme heat, which are known risk factors for self-harm.
This research builds on previous findings linking extreme heat to higher rates of suicide and mental health-related hospital admissions, as highlighted in Australia's National Climate Risk Assessment. The collective evidence points to heightened stress, anxiety, and the aggravation of psychiatric conditions in response to unusually warm temperatures, underscoring the broader impact of climate change on the mental well-being of young people.
The findings have important practical implications for health policies, which currently tend to focus on physical heat-related illnesses. The researchers advocate for a broader approach that includes mental health support during periods of extreme heat, particularly for vulnerable young populations.