Randomization and Blinding
Participants were randomized to the Mello or a control group using a computer-generated randomization table, with block sizes of 6 and 8, and stratified based on whether the participant was receiving psychological or other mental health treatment at the time of study participation. The randomization table was created by a researcher independent of the research team and uploaded into REDCap (Research Electronic Data Capture; Vanderbilt University). Researchers randomized participants following the completion of informed consent and baseline questionnaires using the REDCap application. Therefore, allocation was concealed from the researchers’ enrolling participants until the end of the baseline assessment. Owing to the nature of the intervention, the study participants were not blinded to the condition. As all outcomes were assessed via self-reported questionnaires, the researchers were also not blinded to the condition.