Procedure
WL
Participants were invited to join the study at the beginning of the academic year (September 2020) on the university’s official website. Eligible individuals received information about the study and gave their written informed consent prior to their inclusion. Then, all participants completed online assessments during the week before starting the program (i.e., pre-intervention assessment), during the week after the completion of the program (i.e., post-intervention assessment), and in the two-month follow-up (i.e., follow-up assessment). Afterwards, participants were randomized to either CCT or WL. The CCT was administered online (in a group format) due to the social-distancing measures during the COVID-19 pandemic. Participants received course credits and a book as a reward for their participation in the study.