There are two astonishing facts about how we live that I think are closely related. The first is that by 2050, two of every three people on Earth will reside in a city. The second is that almost one in five adults globally is dealing with a mental illness.
Why do I think these two statistics are linked? Because by incorporating nature and natural areas into the places where most of us live, we automatically address mental health issues. Nature is the connecting dot.
And now, an international team of researchers, led by scientists from Stanford University and the University of Washington, have created a framework for how city planners, developers, landscape architects and others can integrate nature into urban areas to improve residents’ mental health.
They additionally hope their model will be especially useful in considering the possible mental health repercussions of adding pockets of nature in underserved communities.
Green city spaces and mental health
The benefits of nature and green spaces have long been known. A great deal of work has been done on how urban design can improve cognitive functioning—such as improving attention, creativity, imagination and memory—and physical health. For example, trees are planted in cities to improve air quality to reduce lung diseases or decrease urban heat island effects, and parks are built in specific neighborhoods to encourage physical activity. But these actions don’t usually directly factor in the mental health benefits that trees or a restored park might provide.
There are, however, important relationships between accessible green spaces and mental health, including:
• Mental health and air pollution. For years, air pollutants have been implicated in various health outcomes, notably cardiovascular and respiratory diseases. The effects on mental health conditions are less well studied, but there is increasing evidence of a link between air pollution and depression. There is also evidence of links between air pollution and autistic spectrum disorders in early life and psychotic disorders in later life.
•Mental health and exercise space. Regular exercise is as effective as antidepressants for treating mild to moderate depression. Exercise also improves some symptoms associated with attention deficit hyperactivity disorder, anxiety, dementia, schizophrenia, low self-esteem and stress.
By using natural spaces to make bicycling and walking more attractive than driving, we can increase the opportunities for residents’ to exercise and, in the process, improve their mental health. Parks with running routes, walking loops and spaces for football pitches and outdoor gyms should be prioritized.
•Mental health and sleep. Research has shown that good sleep fosters better mental health and emotional resilience, whereas poor sleep is associated with negative thinking. People with insomnia are four times more likely to develop depression, and depressed people with insomnia are less likely to respond to treatment and are at higher risk of relapse. More than half of the people with anxiety disorders have sleep problems, and poor sleep can worsen symptoms and prevent recovery.
Yet cities can erode sleep patterns with increased ambient noise and light pollution. Along with good building insulation, walls and other sound barriers, green spaces with trees can help prevent urban noise from disrupting sleep.
• Mental health and places to socialize. One of the most important opportunities for promoting good mental health is natural, positive social interactions—from close, confiding relationships to feeling part of a community. Social interactions build our empathy, self-confidence and self-esteem and mitigate feelings of anxiety, isolation and loneliness.
To promote mental health, city planners should develop parks with chances for natural, daily social interactions to occur by providing benches, chess tables and pedestrian plazas for community events.
• Mental health and transportation. Living near public transport connections is associated with better mental health, particularly for older people. Stressful commutes are associated with aggression, anxiety, poor sleep and stress. Commuter stress is highest for car drivers, moderate for public transit-users and lowest for cyclists and walkers. Bikeshares, bike lanes and walking infrastructure in our city parks can improve people’s mental health.
While it’s certainly true that mental health problems exert a huge impact on cities, our cities can do a lot to improve our mental health.
Ecosystem services and a nature-inclusive model
This new study demonstrates that mental health should be one of the newest metrics to be considered an “ecosystem service,” a benefit people receive from the natural environment. Eventually, the Stanford Natural Capital Project plans to build the mental health ecosystem service into its software platform InVEST, which helps city planners and other decision-makers map and value the many services—such as flood risk mitigation, recreation opportunity and water purification—that nature provides to people.
In creating their framework, the researchers write that city planners should consider:
• the elements of nature included in a project, say at a school or across the whole city;
• the amount of contact people will have with nature;
• how people interact with nature;
• and how people may benefit from those interactions, based on the latest scientific evidence.
A natural buffer and environmental justice
Hopefully, this model will eventually be used to help address health disparities in underserved communities, as well. The fact that contact with nature helps to buffer against negative cognitive, physical and mental health impacts means that access to green landscapes is not only a health matter but one of environmental justice, too.
In all of human history, people have never been so disconnected from nature. Hand and hand with this trend is a significant increase in urban living and in mental health disorders worldwide. Bringing nature back into our cities will reverse the flow of these streams and create a pool of total, whole health.
Here’s to finding your true places and natural habitats,