Long-term effectiveness of cognitive behavioral therapy (CBT) for children and adolescents in routine care

This study examines the long-term, cross-diagnostic effectiveness of cognitive behavioral therapy (CBT) in children and adolescents treated under routine outpatient care conditions at the Research and Treatment Centre for Mental Health in Bochum, Germany. Analyses will be based on pre-existing clinical data (2019–2025) including standardized symptom measures (Strengths and Difficulties Questionnaire, SDQ) and ordinal self-rated follow-up assessments collected 6, 12 and 24 months after treatment completion. Pre-post and follow-up changes will be analysed using nonparametric Wilcoxon signed-rank tests with rank-biserial effect sizes and 95% confidence intervals. Associations between follow-up SDQ scores and ordinal treatment-success ratings will be examined via partial Spearman correlations controlling for baseline SDQ to account for initial symptom severity. Sensitivity analyses will include SDQ change scores, standardized transformations and ordinal regression models. The study aims to provide robust evidence on the durability of CBT outcomes across diagnostic groups in youth treated under routine care conditions.