Fig. 2

CES-D score changes. (A) The intervention significantly decreased self-reported depression CES-D questionnaire. Following the intervention, CES-D (depression scale) score was reduced by 26.6% with a large effect size (d = − 0.829, p = 0.004). Data shown in boxplot, the central mark indicates the median, and the bottom and top edges of the box indicate the 25th and 75th percentiles, respectively. The square mark indicates the mean level. (B) Pre- and post-intervention depression severity categories⁵⁷. The percentage of participants meeting the clinical cut-off for depression decreased by 18%, and the percentage of participants classified as “no depression” according to the clinical cut-off scores increased by 18%.