The Efficacy of the Unified Protocol for Emotional Disorders in Children and Adolescents: A Systematic Review and Meta-Analysis

Transdiagnostic treatments such as the Unified Protocol for Emotional Disorders for Children and Adolescents (UP-C/A; Ehrenreich-May et al., 2017a) aim to target shared mechanisms across mental disorders and to achieve positive treatment outcomes. Several studies investigated the UP-C/A with promising results regarding the improvement of internalizing symptoms. However, there is currently no meta-analysis investigating the efficacy across the existing studies. In this preregistered systematic review and meta-analysis (PROSPERO CRD42023474832), we aimed to analyze whether the UP-C/A is effective in reducing internalizing symptoms (primary outcome) and secondary outcomes such as emotion regulation in comparison to control treatments, from pre- to post-treatment and follow-up. We also examined whether context-dependent variables (i.e., sample and treatment characteristics) were predictors of the effects of the UP-C/A. We included 21 studies (9 RCTs, 11 uncontrolled studies, 1 single-case experimental study) with a total of N = 994 participants. For internalizing symptoms, we found moderate controlled effects post-treatment (g = 0.58, p = .014) and at follow-up (g = 0.79, p = .003). Uncontrolled effects were large in both cases. We also found moderate to large effects for secondary outcomes (i.e., emotion regulation, global severity of psychopathology, global functioning). Treatment format did not show an impact on efficacy. Overall, our findings suggest that the UP-C/A constitutes an effective treatment for internalizing symptoms in children and adolescents that can be offered in different treatment formats. However, more research is needed to draw robust conclusions regarding specific treatment mechanisms underlying these effects.Keywords: Adolescents, Children, Emotional disorders, Meta-analysis, Systematic review, Transdiagnostic, Unified protocol