Impact of the Happy Classrooms Programme on psychological well-being, school aggression and positive school climate in secondary education students: A mindfulness and character strengths-based intervention.

This study sought to evaluate the efficacy of a brief version of the Happy Classrooms Programme in psychological well-being, school aggression, and positive classroom climate. Likewise, this study also aimed to identify which intervention effects could be attributed to the development of mindfulness. Finally, the last target of this study was to evaluate the implementation fidelity and the acceptability of the programme. Multiple linear regression and longitudinal mediation analyses were performed with a sample of 524 students (49.8% boys and 50.2% girls) with a mean age of 13.6 years. Results provided evidence of the efficacy of the intervention in the majority of variables. For Mindfulness, Depressive Symptomatology, Perceived Stress, Competence, Emotional Attention, Identified Regulation, External Regulation, and Amotivation, the intervention proved efficacious only when pre-treatment levels of mindfulness were high, and sometimes also medium. For Self-esteem, Satisfaction with Life, Relatedness, Emotional Repair, Physical Aggression, Relational Aggression, Affiliation, and Teacher Support, intervention effects were irrespective of pre-treatment levels of mindfulness. Mediation analyses found evidence of longitudinal mediation effect of mindfulness on the relation between the intervention and most outcome variables. Implementation data showed that total time implemented by the teachers varied among them and that the programme was not highly acceptable by most students. Our findings point out that Happy Classrooms Programme may promote psychological well-being and positive classroom climate, and reduce school aggression in students by increasing mindfulness levels.