The Focus is the Prevention and Promotion of Mental Well-being and is a Universal Delivery Intervention

The goal of this clinical trial is to assess the efficacy of the Unified Protocol for the Transdiagnostic Treatment of Emotional Disorders for Adolescents (UP-A; Ehrenreich-May et al., 2018) as a universal school-based preventive intervention (UP-A Kind) in adolescents aged 11-18. This intervention aims to prevent emotional symptoms and improve adolescents' mental well-being in school setting, assessing changes in transdiagnostic processes. Researchers will compare an experimental group and a control group. Participants will participate in eight weekly sessions and will be assessed at 4 time points (pre- and post-treatment and 3-, 6- and 12-month follow-up). Control group participants will receive no intervention and will be assessed at the same time points.