Statistical analyses
To test the effects of our treatment we applied generalized estimating equations (GEE) for repeated measures. The GEE includes an autoregressive correlation structure that considers correlation between repeated measurements on the same participant. Furthermore, to ensure that the groups are comparable at the beginning of the study, we tested whether baseline scores between the groups were different (Wilcoxon test). We also tested differences between symptoms before and during the pandemic (Wilcoxon test). Diary data was analyzed by comparing the mean of the first three days with the mean of the last three days.