摘要:Background Anxiety disorders are prevalent among adolescents and may have long-lasting negative consequences for the individual, the family and society. Cognitive behavioral therapy (CBT) is an effective treatment. However, many anxious youth do not seek treatment. Low-intensity CBT in schools may improve access to evidence-based services. We aim to investigate the efficacy of two CBT youth anxiety programs with different intensities (i.e., number and length of sessions), both group-based and administered as early interventions in a school setting. The objectives of the study are to examine the effects of school-based interventions for youth anxiety and to determine whether a less intensive intervention is non-inferior to a more intensive intervention. Methods/design The present study is a randomized controlled trial comparing two CBT interventions to a waitlist control group. A total of 18 schools participate and we aim to recruit 323 adolescents (12-16 years). Youth who score above a cutoff on an anxiety symptom scale will be included in the study. School nurses recruit participants and deliver the interventions, with mental health workers as co-therapists and/or supervisors. Primary outcomes are level of anxiety symptoms and anxiety-related functional impairments. Secondary outcomes are level of depressive symptoms, quality of life and general psychosocial functioning. Non-inferiority between the two active interventions will be declared if a difference of 1.4 or less is found on the anxiety symptom measure post-intervention and a difference of 0.8 on the interference scale. Effects will be analyzed by mixed effect models, applying an intention to treat procedure. Discussion The present study extends previous research by comparing two programs with different intensity. A brief intervention, if effective, could more easily be subject to large-scale implementation in school health services. Trial registration ClinicalTrials.gov, NCT02279251 . Registered on 15 October 2014. Retrospectively registered.