RESUMO
BACKGROUND: Loneliness and depressive symptoms are prevalent among Finns. OBJECTIVES: This study, which analyzes nationwide data from 149,986 students aged 13-18 years in Finland, focuses on the mediating effects of social inclusion and loneliness in the association between school belonging and depressive symptoms. METHOD AND RESULTS: The analysis of variance showed that boys reported higher levels of school belonging and social inclusion, whereas girls reported higher levels of loneliness and depressive symptoms. Mediation analysis showed that social inclusion and loneliness partially mediated the effect of school belonging on depressive symptoms, but that social inclusion's effect was much greater than loneliness's. By focusing on the moderating role of sex, it was discovered that social inclusion significantly mediated depressive symptoms in girls more than boys. CONCLUSION: The importance of social inclusion in preventing depressive symptoms was highlighted in the discussion.