A study led by the Barcelona Institute for Global Health (ISGlobal), a center supported by the La Caixa Foundation, and the Idibell in L’Hospitalet de Llobregat (Barcelona) has found that exposure to high ambient temperatures is associated with lower connectivity in three brain networks in preadolescents, suggesting that heat can impact brain function.
The study, published in the ‘Journal of the American Academy of Child & Adolescent Psychiatry’, was carried out in collaboration with the Erasmus University Medical Center (Erasmus MC) in Rotterdam (Netherlands) and the Biomedical Research Networking Center, ISGlobal reported in a statement on Thursday.
The study included 2,229 children aged 9 to 12 from the ‘Generation R’ cohort in Rotterdam, whose functional connectivity data of brain networks — how brain regions communicate — were evaluated using magnetic resonance imaging.
Daily average temperature estimates were obtained from the UrbClim urban climate model developed by the Flemish Institute for Technological Research, using daily mean values for the period 2013-2015.
LOWER FUNCTIONAL CONNECTIVITY
Higher ambient temperature during the week prior to the MRI evaluation was associated with lower functional connectivity within the medial-parietal, salience, and hippocampal networks, essential for proper brain function.
This suggests that brain areas may work less synchronously, affecting processes such as attention, memory, and decision-making.
The results indicate that the association between high temperatures and lower functional connectivity was more intense the day before the brain scan and gradually decreased in the following days, while low temperatures were not related to functional connectivity.
Idibell researcher and lead author of the study, Laura Granés, stated that dehydration could explain the results, as children are «particularly susceptible» to fluid loss when exposed to heat.
TEMPERATURES AND MENTAL HEALTH
The same research team revealed in another study that exposure to cold and heat can influence psychiatric symptoms — anxiety, depression, and attention problems — and other studies have linked lower connectivity within the salience network to suicidal ideation and self-harm behaviors.
«High temperatures could decrease the functional connectivity of this network, indirectly contributing to a higher risk of suicide in individuals with preexisting mental health problems,» concluded Idibell researcher and University of Barcelona author of the study, Carles Soriano-Mas.