Interacting with nature improves cognition and affect for individuals with depression.
Level 2 - randomized trial
Individual randomized crossover trial
PubMed 22464936 · doi:10.1016/j.jad.2012.03.012
What was done
Twenty individuals diagnosed with major depressive disorder (MDD) completed a counterbalanced within-subjects crossover study. Mood and short-term memory span were measured at baseline using the Positive and Negative Affect Schedule (PANAS) and the backwards digit span (BDS) task. Participants were primed for rumination by reflecting on an unresolved negative autobiographical event before taking a 50-minute walk in either a natural or an urban setting. Mood and memory were reassessed post-walk. One week later, participants repeated the protocol in the alternate environment.
What was found
Participants showed a significantly greater increase in memory span following the nature walk compared to the urban walk (p < .001, partial η² = .53). Mood increases were also observed, though changes in mood did not correlate with changes in memory span. Absolute numerical scores for mood and memory were not reported in the abstract.
Why it matters
This study suggests that brief exposure to natural environments may enhance working memory and mood in individuals with major depressive disorder, indicating potential utility as a low-cost adjunctive behavioral intervention.
Limits
The sample size was very small (n = 20), limiting precision and generalizability. Absolute outcome values and confidence intervals were not provided in the abstract, blinding to the intervention environment was impossible, and long-term durability of the observed improvements was not evaluated.
Cited by
- partial Head-to-head comparison studies show that aerobic walking in a natural environment produces a profound antidepressant and mood benefit not observed when walking in an urban environment.