Nature contact by window opening and depressive symptoms among Older Adults: A cross-sectional analysis of the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND Recent evidence suggests that window-view and window-ventilation may contribute to mental wellbeing. Compared to their younger counterparts, older adults spend more time at home and have less contact with natural environments due to social isolation and physical decline. However, the association of residential window-opening with depressive symptoms is understudied among older populations. METHODS We used data from a community-based cohort study conducted in 23 provinces of China including 13,125 adults age 65 years or older (mean age: 83.8 years [SD: 11.1]). We created the window opening index (WOI) as a proxy of window-view and window-ventilation, leveraging relevant data on self-reported frequencies of manual window opening at home. Depressive symptoms were assessed by the 10-item version of the Centre for Epidemiological Studies Depression scale no fewer than 10. We used multivariate logistic regression model to examine the association between window opening and depressive symptoms. RESULTS In the multivariate logistic regression model controlling for a set of well-designed mood-influencing environmental and individual-level covariates, a protective effect of window opening on depressive symptoms was observed, with 16% lower odds per interquartile increment in WOI (odds ratio: 0.84, 95%-CI: 0.81-0.87). Subgroup analyses indicated that the beneficial effects were more pronounced among those with higher socioeconomic status (higher levels of education, urban residents) and better surrounding environments (lower exposure of ambient fine particular matter, proximity to park, or higher levels of residential greenness). DISCUSSION The results point to the benefits of well-designed household window-opening environments on the mental health of older populations and suggest a synergistic effect of window-opening and favorable surrounding natural environment.