Abstract: This observational study examined the changes during inpatient cognitive-behavioral treatment (CBT) of adolescents with chronic anxious-depressive school absenteeism with or without comorbid disruptive symptoms. 147 adolescents (aged 12-18years) with a specific phobia or other anxiety disorder or a depressive episode or a mixed disorder of conduct and emotions and who had completely ceased to attend school or showed irregular school attendance underwent an inpatient cognitive-behavioral treatment. A further 16 patients aborted the treatment during the first day and were not included in the analyses. The treatment was manual guided and also included parents. Assessments were made pre-inpatient treatment, immediately post-inpatient treatment and at 2-month follow-up. School attendance was the primary outcome variable and secondary outcomes were composite scores of a range of adolescent- and parent-rated mental health problems. Overall, results show a considerable decline of school a