... Regarding the participants, most of the studies were addressed to gatekeepers as school staff members, educators, university professors, college or high school students, social workers, and nonclinical employers in hospitals (twelve studies, 31.4%) [74,76,81,82,86,87,90,[92][93][94]100,103]; nine studies were addressed to youth, adolescents, college or high school students as vulnerable and high-risk populations [18,30,75,80,83,95,96,98,99], ten to health professionals in training [50,72,73,78,79,84,85,88,89,102], such as medical school students, nurse practitioners, residents, physicians, and pharmacy staff members. Two studies were addressed to the adult population [77,91], and finally, three had mixed recipients (i.e., schoolteachers and mental health professionals or gatekeepers and adolescents, as in the SEYLE study) [18,97,101]. ...