Effectiveness of Nature Therapies for Treatment of Posttraumatic Stress Disorder: A Systematic Review and Exploratory Meta-Analysis.

BACKGROUND: The global prevalence of mental health disorders, including posttraumatic stress disorder (PTSD), has increased substantially; engagement with nature has been shown to support recovery. This systematic review and exploratory meta-analysis examined the application and effectiveness of nature therapies in the treatment of PTSD for the clinical adult population. METHODS: In this review, 11 studies were included following a systematic process using the PRISMA framework, encompassing a total sample of 654 participants. A exploratory meta-analysis was conducted based on six of these studies. RESULTS: Most studies showed a significant reduction in PTSD symptoms after participation in nature therapy. The exploratory meta-analysis indicated a large effect size for pre- to post-intervention outcomes (Cohen's d = -0.82 [-1.14, -0.50] (k = 3), p <.001), but no significant effect size when comparing experimental and control groups (Cohen's d = -2.11 [-4.61, 0.39] (k = 3), p =.098). DISCUSSION: However, these estimates are based on a small number of studies, and the exploratory nature of the analysis warrants cautious interpretation. Overall, the findings suggest that nature therapy may offer beneficial effects as a complementary approach in the treatment of PTSD.