The authors found that the risk of hospitalizations increases by 4% every 10-degree increase in mean daily temperatures. While similar estimates were found across all sex and age categories, the study suggests that some mental health subgroups seem to be particularly vulnerable to heat. «We found that patients with developmental disorders and schizophrenia seemed to be more affected by ambient temperature in this study. This finding can be explained, for example, due to the fact that many patients with developmental disorders (e.g., autism) show altered sensitivity to external environmental hazards. Patients with schizophrenia seem to have a limited ability to compensate to heat stress, due to, for example, the use of antipsychotic drugs» says Marvin Bundo, first author of the study and PhD student at the Climate Change and Health research group at the Institute of Social and Preventive Medicine and Oeschger Centre for Climate Change Research at the University of Bern.
The study demonstrates that rising temperatures have an effect on mental health – even in temperate climates. In the absence of interventions targeted at vulnerable populations, the direct impact upon mental health would amplify in the future due to climate change. These findings would support policy-makers in the development of interventions to counteract the negative health impacts of climate change and its human, social, and financial consequences on these vulnerable groups. «There is growing evidence suggesting that patients with mental illnesses are more vulnerable to climate change, as they have fewer resources to protect themselves against environmental stressors. Current policies should therefore consider them as vulnerable groups to which tailored public health interventions must be targeted» says Dr Ana M. Vicedo-Cabrera, senior author of the study and head of the Climate Change and Health research group.
This was a multidisciplinary study, including experts from different research fields. «This work is the result of a collaboration between experts in epidemiology, psychiatry and climate. The collaboration was exciting in every respect. It arose from my observation of conspicuous accumulations of admissions or empty beds in the University Psychiatric Services in Bern. This led to the contact with the team of climatologists and epidemiologists. A truly translational approach with a view beyond one's own disciplines,» says Prof. Dr. med. Thomas Müller, senior author of the study and head of Privatclinic Meiringen and researcher at Translational Research Center, University Hospital of Psychiatry and Psychotherapy University of Bern.