A study led by Waseda University and New York University reveals that increasing park density may reduce suicide rates.
Tokyo’s rapid urbanisation brings with it not just skyscrapers but also rising mental health concerns. Amidst this concrete jungle, a new study suggests that green spaces are more than just aesthetic enhancements—they’re a lifeline.
The study, led by Wenhao Jiang of New York University and colleagues Andrew Stickley and Michiko Ueda from Waseda University, analysed nearly four decades of data from 1975 to 2014. Published in the journal Social Science & Medicine, the research uses spatial panel data analysis to investigate the impact of park density on suicide rates across Tokyo.
By examining 886,440 cases of suicide alongside changes in urban greenery, the researchers were able to identify a consistent pattern: areas with more parks saw significantly lower suicide rates, especially among women and older adults. Their analysis revealed that in large urban centres, every incremental increase in park density per 1,000 people was linked to a marked reduction in suicide rates. This relationship remained even after adjusting for socio-economic factors and population density, suggesting a protective effect of green spaces against mental distress.
The team’s motivation stemmed from the need to address high suicide rates in Japan, which has one of the highest rates among developed countries. They hypothesised that increasing urban green spaces might be a preventive measure against mental health crises.
“By demonstrating that parks are not merely recreational spaces but vital public health resources, our findings pave the way for integrating green spaces into urban development strategies to enhance community well-being,” says Jiang.
Moving forward, the team recommends exploring how the ‘greenness’ of green space affects the reduction in suicide rates. Studying the qualitative aspects of green spaces, such as park design and maintenance, is needed to understand how these factors influence their protective effects. Furthermore, the team is interested in expanding their research to include children and adolescents to know the role of green spaces in their psychological well-being.
Sources: Jiang, W., Stickley, A., & Ueda, M. (2021). Green space and suicide mortality in Japan: An ecological study. Social Science & Medicine, 282, 114137.