Green Spaces Linked to Lower Hospital Admissions for Mental Disorders
A new study published in The BMJ’s climate issue has found that higher levels of greenness are associated with lower risks of hospital admissions for mental disorders. The analysis, which spanned two decades and included data from seven countries, revealed that the protective effect of green spaces on mental health increases with greater exposure, with no clear threshold.
Mental well-being is a global challenge, with an estimated 1.1 billion people experiencing mental disorders in 2021. These conditions contribute to 14% of the global disease burden, leading to significant economic and societal costs. The study highlights the potential benefits of exposure to green spaces in reducing the risk of mental disorders, providing valuable insights for urban design and health policy.
The research analyzed 11.4 million hospital admissions for mental disorders across 6,842 locations in Australia, Brazil, Canada, Chile, New Zealand, South Korea, and Thailand from 2000 to 2019. The study considered all-cause mental disorders as well as specific categories such as psychotic disorders, substance use disorders, mood disorders, behavioral disorders, dementia, and anxiety.
Greenness was measured using the normalized difference vegetation index (NDVI), a satellite-derived metric for assessing vegetation levels. The study accounted for factors such as population levels, weather conditions, air pollutants, socioeconomic indicators, and seasonality. Results showed a 7% reduction in hospital admissions for all-cause mental disorders associated with local greenness, with stronger associations observed for substance use disorders, psychotic disorders, and dementia.
While the protective effects of green spaces varied across countries and disorders, urban areas showed the strongest associations. The study estimated that approximately 7,712 hospital admissions for mental disorders could be prevented annually through increased exposure to greenness in urban areas. Seasonal patterns in urban areas further emphasized the role of climate and weather conditions in shaping the use and perception of green spaces.
The researchers emphasized the need for further exploration of the differential effects of various types of green spaces on mental health outcomes. They also highlighted the importance of assessing the quality and accessibility of green spaces in urban environments. Overall, the study suggests that greening interventions could have significant benefits for mental health, leading to reduced healthcare costs, improved workplace productivity, and enhanced community well-being.
Future research should focus on understanding the specific mechanisms through which green spaces impact mental health outcomes and explore strategies to enhance the availability and quality of green spaces in urban settings. By leveraging the potential benefits of green spaces, policymakers and urban planners can contribute to promoting mental well-being and creating healthier, more sustainable communities.
