05/24/2012 08:46 EDT | Updated 07/24/2012 05:12 EDT

A Walk a Day Keeps the Depression at Bay

Can interacting with nature be therapeutic for individuals with major depressive disorder? In a recent study published in The Journal of Affective Disorders, my collaborators and I found that individuals who were diagnosed with major depressive disorder gained some therapeutic benefits after taking a 50-minute walk in nature vs. taking a 50-minute walk in a traffic-heavy urban environment.

These participants increased their short-term memory capacity by 16 per cent after the nature walk, but did not show any significant benefits after the urban walk. Interestingly, mood improved significantly after both walks, but did not correlate with the memory benefits. This indicates that the memory benefits were not due to simply putting people in good moods. To go a step further, participants in our study were primed to think about a painful negative memory before going on the walks, thus putting participants in a bad mood. However, even being primed to think about a negative memory did not mitigate the salutary value of the walk.

These results are promising for a number of reasons. First, they suggest that simple activities, such as a walk in the park, may have psychological benefits. Second, there are no obvious costs to taking a walk in a park other than time, and you may even lose a few calories!

But let me make one point very clear, I'm not suggesting that taking nature walks replace clinically-tested and validated therapies such as medication and psychotherapy. Those interventions work and have been much more rigorously tested and validated compared to interacting with nature. I do, however, think that results from our study should initiate conversations, and more research into activities that we can all do to supplement and enhance current interventions to improve our overall health.Physical exercise and mindful meditation practice would be two other such examples of supplementary activities.

Lastly, I'm not suggesting that interacting with nature is a panacea, capable of healing all human illnesses and maladies. However, we are finding that even brief interactions with nature can have significant impacts on human cognitive functioning. Therefore, it will be important for us to uncover the boundaries and limitations of the effects to determine just how far nature can take us.