More green spaces in cities may decrease demand for mental health services, new research suggests
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City dwellers who have more exposure to urban green spaces require fewer mental health services, according to a new study from the Texas A&M University School of Public Health.
The study, published in the International Journal of Environmental Research and Public Health, was conducted by Dr. Jay Maddock, Regents Professor in the Department of Environmental and Occupational Health, Dr. Omar M. Makram from Augusta University and colleagues from the Center for Health and Nature, Texas A&M Health, Houston Methodist and Texan by Nature.
The researchers measured urban greenness with the online platform NatureScore, which uses numerous data sets related to factors such as air, noise and light pollution, parks and tree canopies to calculate the amount and quality of natural elements for any address in the United States and other countries.
For addresses, they used data on mental health visits aggregated at the ZIP code level from Texas Hospital Outpatient Public Use Data Files from 2014 to mid-2019. The researchers selected 61,391,400 adult outpatient encounters in Texas cities for depression, bipolar disorders, stress and anxiety.
“The association between exposure to nature and better mental health is well established in the United States and elsewhere, but most studies use just one or two measurements of this exposure,” Maddock said. “Our study was the first to use NatureScore, which provides more complex data, to study the correlation between urban nature exposure and mental health.”
The trend for various mental health encounters decreased as the NatureScore of a neighborhood increased, and the rates of mental health encounters were about 50 percent lower in neighborhoods with scores greater than 60. Those who lived in neighborhoods with the two highest NatureScore categories had significantly lower rates of mental health encounters compared to neighborhoods with the lowest NatureScore category.
“We found that a NatureScore above 40—considered Nature Adequate—seems to be the threshold for good mental health,” Maddock said. “People in these neighborhoods have a 51% lower likelihood of developing depression and a 63 percent lower likelihood for developing bipolar disorders.”
Omar, the study’s lead author, noted that these findings could have important implications for urban planning, saying that “increasing green space in cities could promote well-being and mental health, which is critically important given that more than 22% of the adult population in the United States is with a mental health disorder.”