Depression in older adults is a public health challenge. We aimed to clarify the relationship between depression in older adults and three types of neighborhood greenspaces: trees, grasslands, and fields. We utilized data from the Japan Gerontological Evaluation Study (JAGES) performed in 2016. Multilevel logistic regression analysis was used for non-stratified and stratified analyses for the urban–rural regions. The target population comprised 126,878 older adults (age ≥ 65 years) who responded to the depression questions and were living in 881 neighborhoods in Japan. Depression was diagnosed based on a Geriatric Depression Scale score ≥5, and 20.4% of the study population had depression. In the pre-stratification analysis, areas with more greenspaces revealed lower odds of depression (odds ratio (OR) 0.95, 95% confidence interval (CI) 0.85–0.95). In urban areas, more trees correlated with lower odds of depression (OR 0.94, 95% CI 0.89–1.00). In rural areas, moderate amounts of grassland were associated with lower odds of depression compared to areas with fewer grasslands (OR 0.91, 95% CI 0.83–1.00). We found that urban areas with higher tree density and rural areas with moderate amounts of grassland were associated with lower odds of depression.

Introduction Older adult's depression is a public health problem. In recent years, exposure to local greenspace is beneficial to mental health via increased physical activity in people. However, few studies approach the relationship between greenspace and depression while simultaneously considering the frequency, time, and the number of types of physical activity, and large-scale surveys targeting the older adults. Methods Cross-sectional data conducted in 2016 by the Japan Gerontological Evaluation Study was used. The analysis included older adults aged 65 and over who did not require care or assistance, and a total of 126,878 people in 881 School districts. The explanatory variable is the percentage of the greenspace of the area, and the greenspace data used is data created from satellite photographs acquired by observation satellites of the Japan Aerospace Exploration Agency. The objective variable was depression (Geriatric Depression Scale 5 points or more). The analysis method was a multi-level logistic regression analysis. Physical activity was the number of sports-related hobbies, the frequency of participation in sports meetings, and walking time in daily life. Other factors such as personal attributes, population density of residential areas, and local climate were also considered. Results Depression in the survey was 20.4%. The abundance of greenspace was still associated with depression, considering all physical activity. The odds ratio of depression in areas with more greenspace was 0.92 (95% CI 0.87 - 0.98) compared to areas with less greenspace. Conclusions It became clear that areas with many greenspace were still associated with low depression, even considering the frequency, time and number of physical activities. It is conceivable that the healing effect of seeing greenspace, the reduction of air pollution and noise, etc. are related to the lack of depression without going through physical activity. Key messages In Japan, older adults are less depressed when there are many local greenspace. It became clear that areas with many greenspace were still associated with low depression, even considering physical activities.