Are you sitting inside as you read this, at your computer, under fluorescent lights as city traffic blares outside? As summer fades and fall begins, perhaps you’ve placed a cheery nature scene on your computer screen of an autumn wonderland in the glow of a sunny day, and you like to imagine yourself there. But as the leaves start to paint themselves in fiery brilliance under a sky that seems bluer than blue, and the air takes on a crisp freshness, wouldn’t it be oh so good to actually get outside and take a walk in the park?

Actually, it would. A study led by Gregory Bratman, a graduate student in Stanford’s Emmett Interdisciplinary Program in Environment and Resources, the Stanford Psychophysiology Lab and the Center for Conservation Biology, and published in the Proceeding of the Natural Academy of Science, found that walking in nature for 90 minutes is not only soothing, but could lead to a lower risk of depression, something that could be particularly good for urban dwellers.

Down in the city

For city dwellers, it’s no secret that crowded sidewalks, continually honking traffic and perceived rudeness by strangers can be psychological pitfalls leading to anxiety and stress. And lots of us live here: “More than 50% of people now live in urban areas. By 2050 this proportion will be 70%,” the study reports.

But are city dwellers actually more at risk for mental illness? A study published in Environmental Science states: “Meta-analytic studies report that among individuals living in cities, the prevalence of all psychiatric disorders is increased by 38%, of mood disorders by 39%, and of anxiety disorders by 21%, as compared to inhabitants of rural areas.”

Natural areas may be vital for mental health

The Stanford study consisted of two groups of participants walking in either a grassland area scattered with oak trees and shrub or along a traffic-heavy roadway. Participants filled out questionnaires, and the study’s researchers measured heart and respiration rates and took brain scans before and after the walks.

The study reported that, “Participants who went on a 90-minute walk through a natural environment reported lower levels of rumination [repetitive thought focused on negative aspects of self] and showed reduced neural activity in an area of the brain linked to risk for mental illness compare with those who walked through an urban environment.”

“These results suggest that accessible natural areas may be vital for mental health in our rapidly urbanizing world,” says co-author Gretchen Daily, the Bing Professor in Environmental Science and a senior fellow at the Stanford Woods Institute for the Environment, in a Stanford news release. However, co-author James Gross, a psychology professor at Stanford, also notes, “These findings are important because they are consistent with, but do not yet, prove, a causal link between increasing urbanization and increased rates of mental illness.”

An evolutionary link to the natural world

Perhaps we feel better after a walk in nature because as natural beings, it’s simply in our wiring.  A previous Stanford study notes a theory that “nature scenes activate our parasympathetic nervous system in ways that reduce stress and autonomic arousal, because of our innate connection to the natural world. Particular natural landscapes (especially grasslands with clusters of trees) tended to provide human beings with ‘opportunities’ for gain, and places of ‘refuge’ for safety.”

The balm of nature

So that’s why so many of our computer screens feature nature scenes we’d like to be walking in. And why not? Taking a walk may help us snap out of depression and maybe even halt those racing and intrusive negative thoughts. So next time your office mate’s stressed out and ruminating on the negative, tell them to just go take a hike!—they’ll thank you later.

Click here to get inspired by Rose’s easy steps to positively change your mind