Effectiveness of the Unified Protocol for transdiagnostic treatment of emotional disorders in group format in Spain: Results from a randomized controlled trial with 6-months follow-up

Background The present study aims to investigate the effectiveness of the Unified Protocol (UP), a transdiagnostic treatment of emotional disorders (EDs), when applied in a group format in the public mental health system in Spain. Methods 488 participants with a primary diagnosis of ED were randomized to the UP group or to the treatment as usual (TAU; individual, disorder-specific cognitive behavioral therapy). Personality, depression and anxiety symptoms, affect, and quality of life were assessed at pre-treatment, 3 months after treatment onset (coinciding with the end of the UP treatment), and 6 and 9 months after treatment onset (follow-ups). The moderating effect of the treatment condition and the number of sessions received in the evolution of study outcomes was investigated with a linear mixed model analysis. Results A significant improvement in outcomes occurred in both conditions, except for extraversion in the TAU. Improvements in depression, anxiety and quality of life were larger in the UP condition. After the treatment, improvements were maintained at follow-ups in all study outcomes. An interaction between Time*Condition*Sessions was found for depression. Conclusion The results add to the existing evidence on the effectiveness of the UP and may be important for implementation purposes in the Spanish or other similar public mental health systems. Trial registration number NCT03064477 (March 10, 2017).