Study Links Extreme Heat to Doubled Mental Health Admissions in Youth
Extreme high temperatures in warmer months double the risk of young people being admitted to hospital for a mental health condition, according to research from the University of Sydney. The analysis, which examined 720,000 New South Wales hospital admissions of young people aged up to 24, suggests the climate crisis will aggravate the already declining mental health of young people. As extreme temperatures become more frequent due to global heating, heat-related hospital admissions are projected to increase between 6% and 7.7% by the end of the century, the research states.
Study Details and Key Findings
Lead author Dr. Wen-Qiang He of the University of Sydney said: “We found that as temperatures increase, we see admissions for these younger populations increase significantly. The risk doubles in the warm season and triples in the cold season.” The research, published in the Journal of the American Academy of Child and Adolescent Psychiatry, analyzed 720,000 hospital admissions between 2001 and 2022 for young people aged up to 24 with various mental health conditions, including schizophrenia, depression, substance misuse, eating disorders, and self-harm.
Researchers found that when daily average temperatures were in the highest 1% for that day, the risk of hospital admission doubled during warmer months (October to March) and tripled during cooler months. Previous research has also shown that young people in NSW present to hospital with suicidal thoughts and behaviours more often on hotter-than-average days.
Possible Causes and Expert Commentary
The study did not identify the exact mechanisms linking higher temperatures to increased mental health admissions, but the authors proposed several possible causes. In warmer months, higher absolute temperatures may directly affect brain function, with knock-on effects for mental health. Unexpected temperature changes, such as those in winter, could also impair stress coping, sleep, and mood. Dr. Cybele Dey, an adolescent psychiatrist in Sydney and co-author, noted that the short lag between temperature spikes and admissions suggests a physiological response. “These are not mild presentations. There has to be a lot going wrong for a person to be admitted,” she said.
Dr. Hasini Gunasiri, a research fellow at Orygen, a youth mental health research institute, said the findings have “important practical implications” for caring for young people. She explained that during extreme heat, young people might use alcohol or substances to cope with discomfort, irritability, or sleep disruption. Heat can also increase impulsivity and risk-taking behaviours, as well as thoughts of self-harm. “Sleep disruption may be especially relevant here. Poor sleep is a well-established risk factor for suicidal ideation and self-harm in young people,” she added.
Policy Implications and Recommendations
Gunasiri noted that current heat-health policies focus on physical health outcomes like heatstroke and cardiovascular illness, particularly among older adults. “These findings suggest that mental health should also be considered when planning for extreme temperatures, especially for children and young people,” she said. She recommended incorporating mental health messaging into heat warnings to increase awareness among clinicians and families of the potential mental health impacts of heat.
The National Climate Risk Assessment, released last year, warned that extreme heat has been linked to higher rates of suicide and mental health-related hospital admissions, with research pointing to heightened stress, anxiety, and aggravation of psychiatric conditions.
