Association between residential greenspace and mental health among cancer survivors in Shanghai, China

Background: Living near and enjoying visually green landscapes is associated with better mental health, but evidence focusing on vulnerable populations (such as cancer survivors) is sparse. The purpose of this study was to explore the association between residential greenspace and anxiety and depressive symptoms among cancer survivors in Shanghai, China.Methods: In total, 4195 cancer survivors participated in this study from the 2022 Shanghai Cancer Patient Needs Survey. The estimation of residential greenspaces was based on Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). The presence and severity of depressive and anxiety symptoms were assessed by using the Patient Health Questionnaire-2 (PHQ-2) and Generalized Anxiety Disorder-2 (GAD-2). The relation between mental health and green space was assessed using the Generalized Additive Model (GAM) after controlling for relevant individual covariates and contextual characteristics.Results: The prevalence of anxiety and depression in cancer survivors was 36.2% and 28.3% respectively. After multivariate adjustment, each increase in inter-quartile range (IQR) for NDVI in the 250 m buffer (NDVI-250m) was associated with a decrease in PHQ-2 score (triangle score (95%CI): 0.018 (-0.034, -0.002)) and GAD-2 score (triangle score (95%CI): 0.018 (-0.034, -0.002)), respectively. We observed that an increase in IQR for NDVI-250m was associated with a 3.3% (Odds ratio (OR) (95%CI):0.967 (0.943, 0.991)) reduction in anxiety symptoms. More pronounced greenspace-mental health effects were found among young adults (18-65 years) and participants living in suburban areas, compared to young people over 65 and those living in urban areas (P-interaction < 0.05).Conclusions: Higher levels of residential green space are associated with lower risk of depression and anxiety disorders. Our findings will fill the gap in the relationship between green space and mental health among cancer survivors in urban China, and provide new evidence for garden afforestation, community planning and policy- making. To better understand this association, more longitudinal studies are necessary to investigate the mechanisms involved.