Research Shows Urban Trees Stave off Depression

In a piece for The Guardian, Ashley Stimpson reports on new research that shows the importance of tree cover in urban neighborhoods and draws attention to the "tree inequity" that plagues many low-income communities.

"In many cities, a map of urban tree cover reflects the geography of race and income," Stimpson writes. Historic redlining, blamed for housing inequities and disinvestment, also has a significant impact on a neighborhood's trees—or lack thereof. "According to the US Forest Service, previously redlined areas have an average of 23% tree cover, while once-greenlined neighborhoods, living up to their old label, have an average of 43% tree cover."

Trees aren't just about aesthetics: studies show that they mitigate the urban heat island effect and boost residents' physical and mental health. "Summer days in East Baltimore neighborhoods," which are predominantly Black, historically redlined, and lack extensive tree cover, "can be four to 16 degrees hotter than other parts of the city." In such neighborhoods, residents face the risk of heat-related illnesses, higher cooling costs, and poorer air quality. 

Now, research is zeroing in on the mental health effects of city trees. Using "the correlation between prescription antidepressants and tree cover across a range of neighborhoods," a group of researchers in Germany "were able to demonstrate in more material terms than ever before the correlation between trees and mental wellness." Their findings show that having trees within 100 meters of one's home is associated with reduced antidepressant use, a relationship "especially pronounced in residents with low socioeconomic status." The study's authors suggests that "'unintentional' everyday contact" with nature and "easily accessible urban green space" can have a noticeable positive impact on public health.