RESUMO
OBJECTIVE: The aim of this article was to explore the effectiveness of rational emotive and cognitive-behavioral therapy (REBT) in a clinical setting. METHODS: This study included 349 patients of the Albert Ellis Institute who sought psychotherapy from 2007 to 2016. Analyses were conducted by using the intent-to-treat principle, and outcomes were measured after three sessions of therapy (to measure early response) and at the end of 20 sessions. Outcome Questionnaire-45 was used to measure patient functioning. RESULTS: Patients reported significant improvements in their functioning after participating in REBT, with a medium effect size for early response after three sessions of psychotherapy and at the end of the 20 sessions. CONCLUSIONS: The authors' findings documented that REBT can be effectively transported from a research setting to clinical practice.