Randomised controlled trial of cultural-adapted and programme-adopted cognitive behavioural therapy for children and adolescents' anxiety in Japan: protocol for a Multi-, Inter-, and Cross-cultural Clinical Child Study (MIXCS).

INTRODUCTION: The primary objective of the Multi-, Inter-, and Cross-cultural Clinical Child Study (MIXCS) is to evaluate the hypothesis that the effects of cultural-adapted cognitive behavioural therapy (CA-CBT) and programme-adopted cognitive behavioural therapy (PA-CBT) for children and adolescents' anxiety are both superior to a psychological control (moral education control: MEC) for reducing child and adolescent anxiety disorders and symptoms as well as related constructs. The secondary objective is to explore commonalities and differences in therapy factors between CA-CBT and PA-CBT. METHOD AND ANALYSIS: The study has been designed as a randomised, controlled and assessor masked multicentre superiority trial with three groups: CA-CBT, PA-CBT and MEC. Primary outcome is remission of primary anxiety disorders evaluated by independent evaluators. Secondary outcomes are clinician's severity ratings, child self-reported anxiety symptoms, depressive symptoms, cognitive errors and family accommodation, as well as parent-reported anxiety symptoms, and family accommodation. Competence and adherence of treatment, therapy factors in treatment sessions are also measured based on behavioural observation. Finally, satisfaction and comprehension are collected. We aim to recruit at least 99 families for the analysis. Treatment will be delivered weekly for 10 sessions and assessment will be conducted 2 weeks before the treatment (pre), 3 months after the base date when the treatment starts (post), 6 months (six months follow-up) and 12 months (12 months follow-up) after the postassessment. ETHICS AND DISSEMINATION: The MIXCS study was approved by Doshisha University Research Ethics Review Committee, Kwansei Gakuin University Institutional Review Board for Medical and Biological Research Involving Human Subjects and Shinshu University Certified Review Board of Clinical Research. Regardless of the results, the primary outcome will be published in a journal, and if the efficacy and effectiveness of CA-CBT and/or PA-CBT are empirically supported, the authors will encourage dissemination of the programmes including the assessment system through key stakeholders in education, health, and welfare areas. TRIAL REGISTRATION NUMBER: UMIN000038128.