A recent study from the School of Public Health at Texas A&M University proposes that urban residents with better accessibility to green spaces tend to utilize fewer mental health services.
The research, published in the International Journal of Environmental Research and Public Health, was spearheaded by Jay Maddock, Ph.D., a Regents Professor of Environmental and Occupational Health at Texas A&M. Maddock, who also heads the Center for Health and Nature, worked in collaboration with colleagues from Houston Methodist and Texan by Nature for this study.
The research team deployed NatureScore, a rating system that utilizes a multitude of data sets related to elements like air quality, noise and light pollution, parks, and tree cover. The system generates a comprehensive metric representing the natural elements present in any given address in the United States and some other countries, with scores ranging from 0-19 points (Nature Deficient) to 80-100 (Nature Utopia).
Data representing mental health services utilized, presented at the ZIP code level, were procured from Texas Hospital Outpatient Public Use Data Files spanning from 2014 to mid-2019. While these data provided information on patient demographics, employment status, education level, and primary diagnosis, they did not reveal patient identities.
“While previous studies had established a correlation between access to nature and improved mental health, they were often based on limited metrics,” Maddock explained. “Our study, however, is the first to employ NatureScore, offering a more complex dataset to study the relationship between exposure to urban green spaces and mental health.”
The researchers analyzed over 61 million adult outpatient encounters in urban Texas areas, dealing with mental health conditions like depression, bipolar disorders, stress, and anxiety. The collected data spanned 1,169 ZIP codes, with a typical NatureScore midpoint of 85.8. About half of the samples scored high on NatureScore (80+), while roughly 22% scored under 40.
The demographic profile associated with these encounters showcased that 63% were women, 30% aged 65 or older, 54% non-Hispanic white, and 15% Hispanic. At the ZIP code level, 27% of the population held a bachelor’s degree, 58% were employed, 14% lived under the poverty line, and 17% lacked health insurance. Areas with higher NatureScores typically had a larger percentage of older residents, whites, Hispanics, and employed individuals. Conversely, these areas had fewer Black residents, impoverished individuals, or uninsured people.
The investigators noted a trend where mental health visits diminished as a neighborhood’s NatureScore increased. Neighborhoods with a NatureScore above 60 witnessed mental health visit rates about half as frequent. Residents in areas categorized as ‘Nature Rich’ and ‘Utopia’ (the two highest NatureScore classifications) demonstrated considerably lower mental health visit rates than those in areas with the lowest NatureScore rating.
Maddock noted, “A NatureScore above 40 – categorized as ‘Nature Adequate’ –seems to serve as a benchmark for satisfactory mental health. Residents in these zones are 51% less likely to experience depression and 63% less likely to develop bipolar disorders.”
“The results have significant implications for urban planning,” commented the study’s primary author, Omar M. Makram. “Upgrading urban green space could boost wellness and mental health, a crucial finding considering over 22% of the US adult population struggles with a mental health disorder.”
