Compared to randomized controlled trials, studies examining the effectiveness of cognitive behavioral therapy (CBT) in children and adolescents with mental disorders are rare, and a teacher perspective is scarce. The present study investigated the effectiveness of routine CBT in 519 patients aged 6–18 years with mental disorders. Changes in mental health problems were assessed in teacher (Teacher Report Form, TRF) and parent rating (Child Behavior Checklist, CBCL) and were analyzed within the total sample, yielding statistically significant, small to medium effect sizes (teacher rating: d = .74–2.39; parent rating: d = .65–1.18). Changes in a subgroup of patients with elevated symptom scores at treatment start were compared to a historical control group receiving weekly academic tutoring. Net total score effect sizes lay between d = 0.98 and d = 1.29 for teacher rating (parent rating: d = 0.84 to d = 1.01). Nevertheless, a substantial number of patients remained in the clinical range. Symptom changes during family- and patient-based CBT interventions did not differ from treatments including additional school-based interventions, as was also the case for the comparison of treatments with and without additional pharmacotherapy.
