A walk in the park
may have psychological benefits for people suffering from depression.
Zestzfulness, in the last two years, had reported on the
benefits of exercise on our mental health, see HERE, HERE & HERE.
Now, in one of the first studies to examine the effect of nature
walks on cognition and mood in people with major depression, researchers in Canada and the U.S. have found promising evidence
that a walk in the park may provide some cognitive benefits.
The study was led by Marc Berman, a post-doctoral fellow at
Baycrest's Rotman Research Institute in Toronto,
with partners from the University of Michigan and Stanford University.
"Our study showed that participants with clinical
depression demonstrated improved memory performance after a walk in nature,
compared to a walk in a busy urban environment," said Dr. Berman, who
cautioned that such walks are not a replacement for existing and well-validated
treatments for clinical depression, such as psychotherapy and drug treatment.
"Walking in nature may act to supplement or enhance
existing treatments for clinical depression, but more research is needed to
understand just how effective nature walks can be to help improve psychological
functioning," he said. Dr. Berman's research is part of a cognitive
science field known as Attention Restoration Theory (ART) which proposes that
people concentrate better after spending time in nature or looking at scenes of
nature. The reason, according to ART, is that people interacting with peaceful
nature settings aren't bombarded with external distractions that relentlessly
tax their working memory and attention systems. In nature settings, the brain
can relax and enter a state of contemplativeness that helps to restore or
refresh those cognitive capacities.
In a research paper he published in 2008 in Psychological
Science, Dr. Berman showed that adults who were not diagnosed with any illness
received a mental boost after an hour-long walk in a woodland park -- improving
their performance on memory and attention tests by 20 percent -- compared to an
hour-long stroll in a noisy urban environment. The findings were reported by
The Wall Street Journal, The Boston Globe, The New York Times, and in the
Pulitzer Prize finalist book by Nicholas Carr, The Shallows: What the internet
is doing to our brains.
In this latest study, Dr. Berman and his research team
explored whether a nature walk would provide similar cognitive benefits, and
also improve mood for people with clinical depression. Given that individuals
with depression are characterized by high levels of rumination and negative
thinking, the researchers were skeptical at the outset of the study that a
solitary walk in the park would provide any benefit at all and may end up
worsening memory and exacerbating depressed mood.
For the study, 20 individuals were recruited from the University of Michigan
and surrounding Ann Arbor
area; all had a diagnosis of clinical depression. The 12 females and eight
males (average age 26) participated in a two-part experiment that involved
walking in a quiet nature setting and in a noisy urban setting. Prior to the
walks, participants completed baseline testing to determine their cognitive and
mood status. Before beginning a walk, the participants were asked to think
about an unresolved, painful autobiographical experience. They were then
randomly assigned to go for an hour-long walk in the Ann Arbor Arboretum
(woodland park) or traffic heavy portions of downtown Ann Arbor. They followed a prescribed route
and wore a GPS watch to ensure compliance. After completing their walk, they
completed a series of mental tests to measure their attention and
short-term/working memory and were re-assessed for mood. A week later the
participants repeated the entire procedure, walking in the location that was
not visited in the first session.
Participants exhibited a 16 percent increase in attention
and working memory after the nature walk relative to the urban walk.
Interestingly, interacting with nature did not alleviate depressive mood to any
noticeable degree over urban walks, as negative mood decreased and positive
mood increased after both walks to a significant and equal extent. Dr. Berman
says this suggests that separate brain mechanisms may underlie the cognitive
and mood changes of interacting with nature.
The study was supported by a grant from the National
Institute of Mental Health and a private grant from the TKF Foundation.
###
The above story is based on the May 14, 2012 news release by
Baycrest Centre for
Geriatric Care. The research has been published online in the Journal of
Affective Disorders: Marc G. Berman, Ethan Kross, Katherine M. Krpan, Mary K.
Askren, Aleah Burson, Patricia J. Deldin, Stephen Kaplan, Lindsey Sherdell, Ian
H. Gotlib, John Jonides. Interacting
with nature improves cognition and affect for individuals with depression. J Affect Disorders, 2012; DOI:
10.1016/j.jad.2012.03.012
This is interesting. I've heard the same thing about endurance training, as opposed to leisurely walking. There was an interesting article in Time about two weeks ago that indicated that part of the benefit is actually generated by a hormonal effect that occurs as a result of muscular stimulation. I'm especially partial to the suggestion that actually getting outside and experiencing nature seems to be a critical part of the equation. Increased absorption of Vitamin D may have something to do with this as well. Take care.
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