Effects of Horticultural Activities on Mild to Moderate Depression Symptoms: A Randomized Controlled Trial

Objectives: This study was designed to evaluate the effectiveness of participating in horticultural activities on changes in the severity of depression symptoms in adults with mild to moderate depression symptoms. Materials and Methods: In this non-blinded, randomized controlled trial, 102 eligible participants were selected and assigned randomly to experimental and control groups (51 members each). The inclusion criteria were as follows: age of 18 years or above, mild-to-moderate depression symptoms, and willingness to participate in the study. However, the exclusion criteria were physical or mental diseases limiting horticultural activities and using antidepressants.  Both groups received educational worksheets, including behavioral activation, daily activity schedules, breathing training, and relaxation instructions. Moreover, the experimental group participated in weekly three-hour horticultural program sessions for six weeks. The severity of depression symptoms was then appraised at baseline, the end of the intervention, and four weeks after the end of the intervention through the Beck Depression Inventory-II (BDI-II). The repeated measures ANOVA was used for data analysis. Results: The results revealed that the mean BDI-II scores in the horticultural group declined by 5.68 points (P=0.001) and 2.32 points (P=0.016) more than the control group at the end of the intervention and four weeks later, respectively. Conclusion: This study indicated that horticultural activity might mitigate the severity of depression symptoms.