Evaluating the efficacy of a school-based Finnish Gutsy Go programme in enhancing adolescents' positive mental health, experience of social inclusion, and social competence.

The Finnish Gutsy Go programme is a positive youth development intervention designed to enhance adolescents' psychosocial well-being by enabling eighth-grade students to develop and execute good deeds within the community. This study aimed to explore the effect of the Gutsy Go programme on adolescents' positive mental health, experience of social inclusion, and social competence using a quasi-experimental study design. Data were collected with electronic questionnaires at baseline ( = 236 programme participants and = 303 controls) and follow-up two weeks after the programme ( = 126, 54.2% programme participants and = 103, 34.1% controls). Analyses included paired samples -tests and mixed ANOVA analyses. A statistically significant intragroup change across time was detected in the level of cooperation skills among programme participants ((127) = -2.460, = 0.015) but not among controls ((102) = 1.088, = 0.279). Statistically significant main effects were found for the intervention group on the experience of social inclusion ((1, 1) = 9.34, = 0.003, η = 0.040), cooperation skills ((1,1) = 5.28, = 0.020, η = 0.020), and empathy ((1,1) = 6.44, = 0.010, η = 0.030) across time. The Gutsy Go programme could be beneficial in improving adolescents' experience of social inclusion, cooperation skills, and empathy. More studies are needed to address the effects of the programme more firmly.