Extreme temperatures can affect mental health in young people, but the brain processes involved remain unclear. Using resting-state functional MRI, researchers studied how short-term exposure to different temperatures influences brain connectivity in preadolescents. These brain connections are linked to mental health conditions, making the findings necessary for understanding the impact of temperature on young minds.
The study was led by the Barcelona Institute for Global Health (ISGlobal), a center supported by the” la Caixa” Foundation and IDIBELL, in collaboration with Erasmus University Medical Center Rotterdam (ERASMUS MC) and the Networked Biomedical Research Center (CIBER): areas of Epidemiology and Public Health (CIBERESP) and Mental Health (CIBERSAM).
The study analyzed 2,229 children aged 9 to 12 from Rotterdam, Netherlands’s “Generation R” cohort. Researchers used resting-state MRI to examine how different brain regions interact when the children were not doing any tasks. Ambient temperature data, recorded from 2013 to 2015 using the UrbClim urban climate model, matched each child’s home address.
Results showed higher temperatures the week before the MRI were linked to reduced connectivity in brain networks like the medial parietal, salience, and hippocampal networks. These areas are crucial for attention, memory, decision-making, and introspection. The findings suggest that higher temperatures disrupt the brain’s ability to function smoothly.
The formation and development of brain networks during birth
The research found that high temperatures had the strongest impact on brain connectivity the day before the brain scan and reduced over subsequent days. However, low temperatures showed no effect on brain connectivity.
Lead researcher Laura Granés suggests dehydration could be a key factor, as children are more vulnerable to fluid loss in heat, which might disrupt brain network connectivity.
Senior author Mònica Guxens emphasizes that public health measures to protect young people from heat exposure in the face of the climate crisis could help safeguard brain function.
Changes in brain function have been proposed as a link between temperature and mental health, but this is the first study to examine how ambient temperature affects brain networks. The same team previously found that exposure to extreme heat or cold can influence symptoms like anxiety, depression, and attention problems. Other research has shown that lower connectivity in the brain’s salience network is linked to suicidal thoughts, self-harm in depressed teens, and anxiety disorders.
Carles Soriano-Mas, a researcher on the study, suggests that high temperatures might reduce the salience network’s connectivity, which could increase the risk of suicide in individuals with pre-existing mental health issues. While this change doesn’t directly cause suicidal behavior, it might act as a trigger for vulnerable individuals.
Journal Reference:
Granés L., Kusters M. S. W., Ballester J., Essers E., Petricola S., López-Vicente M., Iñiguez C., Tiemeier H., Muetzel R. L., Soriano-Mas C., Guxens M. Exposure to Ambient Temperature and Functional Connectivity of Brain Resting-State Networks in Preadolescents. Journal of the American Academy of Child and Adolescent Psychiatry. DOI: 10.1016/j.jaac.2024.11.023