The effects of walking in nature on negative and positive affect in adult psychiatric outpatients with major depressive disorder: A randomized-controlled study.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 36058362 · doi:10.1016/j.jad.2022.08.121
What was done
This parallel-group randomized controlled trial investigated the impact of a single 60-minute walk in a nature setting compared to an urban setting on affect in adult psychiatric outpatients with major depressive disorder (MDD). Thirty-seven participants (mean age = 49 years) were randomized to either condition. Negative and positive affect were measured with the Positive and Negative Affect Schedule (PANAS) across six time points: pre-walk, halfway during the walk, immediately post-walk, at home before bedtime, 24 hours post-walk, and 48 hours post-walk.
What was found
After controlling for baseline affect, participants walking in nature exhibited significantly lower overall negative affect compared to those walking in urban environments (F(1, 35.039) = 4.239, p = .047). There was no statistically significant difference between groups for positive affect (specific test statistics and group means were not reported in the abstract).
Why it matters
This study provides initial randomized evidence that nature exposure during exercise can reduce negative affect in clinically depressed outpatients compared to walking in built urban environments.
Limits
The sample size was very small (n = 37) and had a higher proportion of female participants. The study tested only a single acute session rather than long-term regular walking, and the abstract lacks group means, standard deviations, effect sizes, and specific test statistics for positive affect.
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.