This study aimed to explore whether walking in nature may be beneficial for individuals
with major depressive disorder (MDD). Healthy adults demonstrate significant cognitive
gains after nature walks, but it was unclear whether those same benefits would be
achieved in a depressed sample as walking alone in nature might induce rumination,
thereby worsening memory and mood.
Twenty individuals diagnosed with MDD participated in this study. At baseline, mood
and short term memory span were assessed using the PANAS and the backwards digit span
(BDS) task, respectively. Participants were then asked to think about an unresolved
negative autobiographical event to prime rumination, prior to taking a 50-min walk
in either a natural or urban setting. After the walk, mood and short-term memory span
were reassessed. The following week, participants returned to the lab and repeated
the entire procedure, but walked in the location not visited in the first session
(i.e., a counterbalanced within-subjects design).
Participants exhibited significant increases in memory span after the nature walk
relative to the urban walk, p<.001, η(p)(2)=.53 (a large effect-size). Participants
also showed increases in mood, but the mood effects did not correlate with the memory
effects, suggesting separable mechanisms and replicating previous work.
Sample size and participants' motivation.
These findings extend earlier work demonstrating the cognitive and affective benefits
of interacting with nature to individuals with MDD. Therefore, interacting with nature
may be useful clinically as a supplement to existing treatments for MDD.
Copyright © 2012 Elsevier B.V. All rights reserved.