“Across neighborhoods of Wisconsin, from the North Woods to the cities, the results are striking,” says Dr. Kristen Malecki, assistant professor of population health sciences at the UW School of Medicine and Public Health. “Higher levels of green space were associated with lower symptoms of anxiety, depression and stress.”
The study, published recently in the International Journal of Environmental Research and Public Health, combines mental-health data from the Survey of the Health of Wisconsin (SHOW) and Landsat 5 satellite data from July 2009 that analyzed how much vegetation was present in each of the SHOW census blocks.
About 2,500 Wisconsin residents from 229 neighborhoods answered an assessment that asked them to rate their symptoms of depression, anxiety and stress. The research team, which was also led by Dr. Kirsten Beyer of the Medical College of Wisconsin in Milwaukee, adjusted the results to make sure they weren’t confounded by race, age, income level, education, marital status, employment and other factors.
They found that across all strata of society, people who lived in a neighborhood with less than 10 percent tree canopy were much more likely to report symptoms of depression, stress and anxiety. So, for example, a poor person living on a logging road in the Chequamegon-Nicolet National Forest was more likely to be happy than a wealthier person living on a treeless block in Milwaukee.
Malecki notes that the study gives credence to the “attention restoration theory,” which holds that more time in nature restores the ability to concentrate and reduces mental fatigue. This idea is also the theme of the book “Last Child in the Woods,” which suggested that indoor lifestyle and more screen time hurt children’s attention spans. It also suggests a relatively simple solution to improving the mental health of poor urban neighborhoods: Plant trees and grass.
“The greening of neighborhoods could be a simple solution to reducing stress,” says Malecki. “If you want to feel better, go outside.”