Describing Roles for a Range of Natural Environments in Adverse Mental Health Outcomes and Neighborhood Social Cohesion across Metro Vancouver, Canada

摘要

In a rapidly urbanizing world, identifying evidence-based strategies to design healthy cities is essential. Although urban living offers increased access to critical resources and can help to mitigate climate change, dense environments are often higher in physical and psychological stressors and lower in social cohesion, which is known to support health. One component of urban form that can ameliorate these stressors is nature: greenspace such as parks and street trees and bluespace such as rivers and oceans. In this project, we applied a Natural Space Index (NSI) previously developed for greater Vancouver, Canada to explore the relationship between the presence, access, and form of natural space and: (1) major depressive disorder; (2) negative mental health; and (3) psychological distress. In addition, we examined associations between the NSI and perceived social cohesion (measured via self-reported sense of community belonging [SoC]), as well as potential mediation of the relationship between nature and mental health via increased SoC. Using data from the nationally representative cross-sectional 2012 Canadian Community Health Survey-Mental Health (sample weighted n=1,930,048), we found no associations between any NSI measures and mental health in models adjusted for 11 demographic, socioeconomic, household arrangement, health, and urban design confounders. However, two measures of publicly accessible neighborhood (500m) nature were associated with increased odds of higher SoC: percentage of public greenspace [AOR=1.05/95%CI=1.00, 1.10 for very strong vs. very weak SoC] and percentage of public natural space [AOR=1.05/95%CI=1.01,1.10 for very strong vs. very weak; AOR=1.04/95%CI=1.01,1.08 for somewhat strong vs. very weak]. In addition, higher levels of SoC were associated with improvements in all three mental health outcomes. These findings suggest an indirect effect of publicly accessible nature on improved mental health via increased social cohesion.