The school is an obvious arena for interventions designed to promote mental health among children. A set of educational techniques named social and emotional learning, which focuses on students' self-control, social competence, empathy, motivation and self-awareness, has shown promising results in the United States. This is a study of the application of a similar method in Sweden (referred to as social and emotional training) for school years 2000/2001 through to 2004/2005.