Development and preliminary evaluation of a group adaptation of the unified protocol for transdiagnostic treatment of emotional disorders in adolescents (UP-A) in a Spanish public mental health center

Anxiety and depression frequently co-occur during adolescence. The Unified Protocol for Transdiagnostic Treatment of Emotional Disorders in Adolescents (UP-A) targets shared emotional mechanisms and has shown promise in individual formats. This study adapted the UP-A to a group format and evaluated its feasibility, acceptability, and preliminary effectiveness in a public outpatient mental health setting in Spain. Thirty-one adolescents ( M = 14.03; 87.1% female) participated in a 16-session group intervention, which included 3 group sessions for parents. A total of 80.65% of participants completed the treatment. Adolescents and parents reported high satisfaction and therapeutic alliance. Significant improvements were observed in adolescent-reported emotional symptoms and emotion regulation strategies, along with parent-reported reductions in depressive symptoms. Clinician ratings indicated reduced diagnostic severity and improved functioning. These findings suggest that the group-based UP-A is feasible, well accepted, and associated with clinical improvement in public mental health care. Further randomized studies are needed to confirm these results. NCT06894368. Date of registration: March 12, 2025 (retrospectively registered).