RESUMO
The present study aimed to assess the efficacy of a group-based, brief transdiagnostic cognitive-behavioral therapy (CBT) program for adolescents with internalizing problems, such as anxiety and depressive disorders, seeking help in a primary health care clinic in Iceland. The group-based CBT program consisted of eight weekly 110-min sessions covering psychoeducation, cognitive restructuring, behavioral activation, exposure, problem-solving, social skills, and mindfulness. The study recruited 53 participants, who were randomly assigned to either receive the group treatment or be placed on a wait-list for monitoring purposes. Measures were taken at baseline, during treatment (week 4), at posttreatment (week 8), and at 2-, 4-month, and 1-year follow-ups. The primary outcome measures were the self-reported total scores of total anxiety and depression using the Revised Children's Anxiety and Depression Scale (RCADS). The study found a significant effect of time and time * treatment interaction on the depression and anxiety total scores. The secondary outcome measures, RCADS parent-rated depression and anxiety total scores, did not show significant effects of time * treatment interaction. However, during naturalistic follow-up, a significant reduction in parent-reported depression and anxiety total scores was observed. The study also observed good treatment adherence, as well as high satisfaction among parents and youth. The results suggest that this group-based, brief transdiagnostic CBT group treatment is feasible and effective in reducing depressive and anxiety symptoms in adolescents with internalizing problems and highlights the importance of addressing comorbidity in treatment.