Green in cities gives mental health a boost

A man examines a fern and other plants within Washington Park Arboretum in Seattle, Washington. (Credit: U. Washington)

A new framework for how city planners can measure the mental health benefits of nature could help incorporate those benefits into plans and policies for cities and their residents.

Almost one in five adults in the US lives with a mental illness. That statistic is similar worldwide, with an estimated 450 million people currently dealing with a mental or neurological disorder. Of those, only about a third seek treatment.

Experts are starting to recognize interacting with nature as one way to improve mental health. A number of scientific studies have shown that nature experiences may benefit people’s psychological well-being and cognitive function. But it has been difficult to find ways to quantify these benefits in a useful manner for cities or organizations that want to integrate nature to improve mental health.

Two children explore the grounds within Washington Park Arboretum
Two children explore the grounds within Washington Park Arboretum in Seattle, Washington. (Credit: U. Washington)

“Thinking about the direct mental health benefits that nature contact provides is important to take into account when planning how to conserve nature and integrate it into our cities,” says Greg Bratman, an assistant professor at the University of Washington School of Environmental and Forest Sciences and lead author of the paper in Science Advances. “The purpose of this paper is to provide a conceptual model of one way we can start to think about doing this.”

Greater happiness, less distress

The researchers first step was to establish a baseline, a collective agreement regarding the understanding of the impacts of nature experience on aspects of cognitive functioning, emotional well-being, and other dimensions of mental health.

“In hundreds of studies, nature experience is associated with increased happiness, social engagement, and manageability of life tasks, and decreased mental distress,” says senior author Gretchen Daily, faculty director at the Stanford University Natural Capital Project.

“In addition, nature experience is linked to improved cognitive functioning, memory and attention, imagination and creativity, and children’s school performance. These links span many dimensions of human experience, and include a greater sense of meaning and purpose in life.”

While this line of study is still emerging, experts agree that nature can reduce risk factors for some types of mental illnesses and improve psychological well-being. They also agree that opportunities for nature experiences are dwindling for many people around the world because of urban growth.

“For millennia, many different cultures, traditions, and religious and spiritual practices have spoken directly to our deep relationship with nature. And more recently, using other sets of tools from psychology, public health, landscape architecture, and medicine, evidence has been steadily gathering in this emerging, interdisciplinary field,” Bratman says.

4 steps for city planners

The study outlines how city planners, landscape architects, developers, and others could eventually anticipate the mental health impacts of decisions related to the environment.

Many governments already consider this with regard to other aspects of human health. For example, trees planted in cities improve air quality or reduce urban heat island effects, and parks built in specific neighborhoods encourage physical activity. But these actions don’t usually directly factor in the mental health benefits that trees or a restored park might provide.

“We have entered the urban century, with two-thirds of humanity projected to be living in cities by 2050. At the same time, there is an awakening underway today, to the many values of nature and the risks and costs of its loss,” Daily says. “This new work can help inform investments in livability and sustainability of the world’s cities.”

The researchers built a conceptual model that can help make meaningful, informed decisions about environmental projects and how they may impact mental health.

It includes four steps for planners to consider:

  1. Elements of nature included in a project, say at a school or across the whole city;
  2. amount of contact people will have with nature;
  3. how people interact with nature;
  4. and how people may benefit from those interactions, based on the latest scientific evidence.

The researchers hope the tool will be especially useful in considering the possible mental health repercussions of adding—or taking away—nature in underserved communities.

“If the evidence shows that nature contact helps to buffer against negative impacts from other environmental predictors of health, then access to these landscapes can be considered a matter of environmental justice. We hope this framework will contribute to this discussion,” Bratman says. “Eventually, it could be developed and potentially used to help address health disparities in underserved communities.”

Additional coauthors are from the University of Washington and Stanford University. The Natural Capital Project, John Miller, the Doug Walker Endowed Professorship, Craig McKibben and Sarah Merner, the Marianne and Marcus Wallenberg Foundation, the Winslow Foundation, the George Rudolf Fellowship Fund, the Victoria and David Rogers Fund, and the Mr. & Mrs. Dean A. McGee Fund supported the work.

Source: University of Washington