Several reports in recent months have added weight to the body of scientific studies about the benefits, both physical and mental, of being outdoors. The recent research, undertaken by researchers at Stanford University, focused on whether or not walking in nature could ease depression.

Researcher Gregory Bratman and his colleagues took 38 healthy people who lived in an urban area and asked them to take a walk. Half walked for 90 minutes through a natural wooded area, and the other half walked along a busy road.

Before and after walking, all participants answered a survey designed to evaluate their tendency to mull over negative thoughts, a habit linked to depression. They also underwent a brain scan that focused on the subgenual prefrontal cortex area of the brain — an area that research has shown to be particularly active during negative self-reflection.

Shortly after their walk, all participants again answered a questionnaire and underwent another brain scan.

Those who walked in the natural area answered the questionnaire differently than they did a couple of hours earlier, and scans showed brain activity decreased in the subgenual prefrontal cortex. However, those who walked in the urban area answered the questionnaire the same as before the walk, and their brain scans showed no difference.

"This provides robust results for us that nature experience, even of a short duration, can decrease this pattern of thinking that is associated with the onset, in some cases, of mental illnesses like depression," Bratman told the Washington Post.