Association between residential greenness and depression symptoms in Chinese community-dwelling older adults

BACKGROUND: Studies of residential greenness and depression symptoms among community-dwelling older adults in China are limited. However, understanding the role of greenness in depression symptoms among older adults can inform depression prevention and interventions. OBJECTIVE: This study explored the relationship between residential greenness and depression symptoms among community-dwelling older adults in China. METHODS: A cluster random sampling method was used to survey 7512 community-dwelling adults aged 60 and above from three towns in Shanghai. Depression symptoms were assessed using the Geriatric Depression Scale (GDS30). Residential greenness was measured using the normalized difference vegetation index (NDVI) and the enhanced vegetation index (EVI). Long-term greenspace exposure was defined as the mean NDVI and EVI in the three years prior to the baseline survey. Controlling for the covariates, the relationship between greenness and depression symptoms was assessed using binomial logistic regression and mixed-effects linear regression. Interaction analysis was conducted to explore which covariates potentially alter the association. We also assessed the mediating role of physical activity. RESULTS: The prevalence of depression symptoms among the participants was 13.72%. Higher residential greenness was associated with lower odds of depression symptoms, after adjusting for covariates. In the logistic regression analysis, the odds of depression symptoms decreased with increasing NDVI and EVI. In linear regression analysis, GDS30 scores decreased with increasing NDVI and EVI. Interaction analyses revealed that higher NDVI and EVI were more protective against depression among male individuals and older adults living with others than among female individuals and older adults living alone. Additionally, physical activity had a masking effect on residential greenness and depression symptoms. CONCLUSION: Higher residential greenness is associated with lower odds of depression symptoms in community-dwelling Chinese older adults. Increasing urban and neighborhood green spaces may contribute to the prevention and intervention of depression symptoms in community-dwelling older adults.