We aim to strengthen the mental health and well-being of young people in the cities of Helmond, Ghent, and Espoo by integrating a scientifically-based factors model into local youth work services. It combines scientific studies and local data, helping policymakers and practitioners to prioritize actions and set up effective interventions. The project will identify key factors, collect data, and set up interventions, fostering collaboration between research, policy, and the youth sector.