Universal school-based prevention program for decreasing the depressive symptoms of high school students on a part-time course: Developing the MIRaES program in Japan

• The effects of previous preventive interventions in high schools were insufficient. • We examine how a new school-based program affects students’ depressive symptoms. • Frequent attenders of program sessions showed no increase in depressive symptoms. • Non-frequent attenders of program sessions saw an increase in depressive symptoms. • Frequent attenders perceived the program as beneficial to their daily lives. The prevalence of depressive symptoms among high school students tends to be high, often serving as a predictor of not only the onset of depressive disorders but also future education-related and economic problems. Although universal school-based programs for preventing depressive symptoms have been implemented worldwide, they have been shown to be ineffective. We examined the reason for this problem from two perspectives: (i) skills learned are not generalized across school environments, and (ii) the program content is not aligned with the context of individual high schools. To address this shortcoming, we developed the Mastery of Interpersonal Relationships and Emotional Skills (MIRaES) program and tested its effectiveness and feasibility using a sample of 120 students on a part-time course at a high school in Japan. We tested the 12-session program over one school year. This program includes certain features that have been shown to be important by previous studies, such as collaborating with schoolteachers to generalize students’ learned skills across school environments and aligning program content with the school context. We quantitatively measured the changes in various psychological aspects, including students’ social skills, cognitive inflexibility, and depressive symptoms, at three time points. Additionally, we qualitatively assessed the program feasibility based on students’ free-text descriptions. The results revealed that depressive symptoms among students who frequently attended the sessions were unchanged, whereas they increased among those who attended the sessions less frequently. Moreover, the qualitative analysis revealed that students who attended the sessions more frequently perceived the program content as useful in their daily lives. Both quantitative and qualitative analysis suggest that the program may help develop emotional regulation skills, which high school students often find challenging. Our findings show that generalizing learned skills across school environments and aligning universal school-based prevention programs in the specific school context can prevent the worsening of depressive symptoms among high school students.