City life can take a serious toll on your mental health. Research has shown that urban dwellers are more likely to suffer from chronic stress and mental illness, particularly depression.
But according to new research, the antidote to those city blues could be as simple as a walk in the park.
A Stanford University study published this week in the Proceedings of the National Academy of Sciences found that walking in nature reduces rumination -- the type of obsessive negative thinking and self-criticism that plays a central role in depression and anxiety disorders.
"Cities are known for higher levels of mental illness such as depression, anxiety, schizophrenia," study co-author Greg Bratman, a doctoral student at the university's School of Earth, Energy & Environmental Sciences, told The Huffington Post in an email. "While the underlying causes are doubtless complex and multifaceted, our findings and those of others highlight the benefits of nature experience."
Take a hike. For the study, the researchers asked 38 mostly healthy men and women to answer questions about their tendency to ruminate, and had them undergo brain scans measuring activity of a particular brain region that tends to light up during this type of thinking. Then, each participant went on a 90-minute walk in either a green space or an urban area.
After walking in nature, participants reported experiencing less rumination, and brain scans revealed less activity in brain regions associated with repetitive negative thinking. Walking through an urban areas, however, had no effect on rumination.
The findings suggest that spending time in nature may improve improve mental well-being by warding off stress and negative thinking.
"Nature experience may help 'buffer' against the stressors of urban life, and might thereby contribute to a lowered risk factor for the onset of depression," Bratman said.
Sadness and the city. If you live in a fast-paced city, you don't have move to the country or plan a camping trip to improve your well-being -- spending time in your city's parks can still be beneficial. A 2013 British study found that walking through urban green spaces can put the brain into a state of meditation.
By bringing more pockets of nature into cities -- whether on rooftops, in empty lots or even along old railroad tracks -- urban planners and policymakers can help improve the mental health of their inhabitants.
"City planners are starting to take account of mental health, in addition to all the other values of nature," Bratman said. "It's important to incorporate these 'psychological ecosystem services' into urban design, to help bring nature to the city, and to improve easy access to these landscapes and nature experience."
It's an issue that will only continue to become more pressing. Today, more than 50 percent of the world's population lives in urban areas, and that number is only growing. By 2050, more than 70 percent of the world's population is expected to live in cities, and many of those people will have little to no contact with nature, Bratman noted.
"We’re in a unique moment in human history," he said. "Never before have so many people lived in cities, and never before have people been so disconnected from the natural world."
Illustration by Jake Reeves for The Huffington Post.