A nationwide Danish study of over 900,000 people indicates that children who grew up with the most green space surrounding their residence had up to 55% lower risk of developing a psychiatric disorder, independent from other known risk factors, than children who grew up with the least green space.
Engemann, Kristine, Carsten Bøcker Pedersen, Lars Arge, Constantinos Tsirogiannis, Preben Bo Mortensen, and Jens-Christian Svenning. “Residential Green Space in Childhood Is Associated with Lower Risk of Psychiatric Disorders from Adolescence into Adulthood.” Proceedings of the National Academy of Sciences 116, no. 11 (2019): 5188–93. https://doi.org/10.1073/pnas.1807504116