Greenspace exposure supports brain development and mental health in adolescents

Researchers have found that greenspace exposure is associated with widespread patterns of structural brain development during early adolescence, which in turn are associated with better academic and mental outcomes. The findings of the study in Biological Psychiatry, published by Elsevier, emphasize the need to integrate natural environments into urban and educational settings and provide key insights for policymakers, parents, and educators to support adolescent well-being.

Previous research has shown that exposure to green spaces positively influences mental health and cognition. However, there is limited understanding of the underlying neurobiological mechanisms of brain development and its potential role in supporting mental well-being in children.

This is the first study to examine the influence of greenspace exposure on structural neurodevelopmental trajectories and which tests whether these trajectories mediate the relationship between greenspace exposure and positive academic or mental health outcomes.

John Krystal, MD, Editor of Biological Psychiatry, comments, "We tend to focus on the detrimental effects and negative aspects of our environment. It is equally important to highlight exposure to green spaces and other positive environments and their contributions to human thriving and resilience."

Investigators analyzed data from more than 7,000 ethnically diverse adolescents in the Adolescent Brain Cognitive Development (ABCD) study from 21 sites across the United States to test the relationship between greenspace exposure at age 9-10 and brain structure two years later as well as change over time. Additionally, they tested whether brain structural development statistically mediated the associations of greenspace exposure with mental health and academic performance.

Co-lead investigator Qingyang Li, MSc, Neuroimaging Department, Institute of Psychology, Psychiatry & Neuroscience, King's College London, explains, "We found greenspace exposure to be associated with brain structural changes at both whole-brain and regional-brain levels. We also found an indirect effect of greenspace exposure on better academic and mental outcomes through both total and regional cortical structure independent of household and neighborhood disadvantage."

They found that greenspace exposure was associated with greater total surface area (SA) and cortical volume (CV), greater cortical thickness (CT) in temporal regions and the insula, lower thickness in the caudal middle frontal and superior frontal gyri, greater SA across several regions, and greater volume of the caudate nucleus, putamen, and nucleus accumbens. In analyses studying change in brain structure over time, higher greenspace exposure was associated with greater growth of total SA, lower average thickness reduction, and reduced total CV growth as well as changes at the regional level.

Adolescence is typified by rapid structural brain development and heightened susceptibility to environmental influences. By 2050, approximately 68% of the global population is expected to reside in cities. Rapid urbanization reduces opportunities for individuals to interact with natural environments and green space.

Co-lead investigator Divyangana Rakesh, PhD, Neuroimaging Department, Institute of Psychology, Psychiatry & Neuroscience, King's College London, concludes, "Children's and adolescents' mental health issues have become a global concern. At the same time, urbanization is rapidly changing the environment and often reducing access to green spaces. This study offers insights for policymakers on how urban planning can help address the growing mental health challenges faced by children and highlights the importance of integrating green spaces into school settings and urban environments."