{
  "abstract": "Introduction Guided parent-delivered cognitive behavioural therapy (GPD-CBT) is an evidence-based, low-burden treatment programme for childhood anxiety disorders with demonstrated efficacy, cost-effectiveness and accessibility. However, it has been tested primarily in Western countries, and the efficacy and cost-effectiveness have not been evaluated in Japanese families. The current study aims to examine GPD-CBT’s efficacy and cost-effectiveness in Japanese samples and explore potential cultural adaptations of the programme.Method and analysis This study is designed as a Bayesian single-blind randomised controlled trial with two parallel groups: GPD-CBT (intervention group) and a waitlist control group. The primary outcome is remission of primary anxiety disorders evaluated through diagnostic interviews by independent evaluators. Secondary outcomes include child and parent-reported child anxiety symptoms, depressive symptoms and life interference. Additionally, measures of parental psychological characteristics, programme acceptability and quality of life are collected. We will conduct qualitative interviews with parents who participated in the programme and therapists who delivered the intervention to explore potential cultural adaptations. We aim to recruit 54–170 families, depending on the results of sequential Bayesian analyses. GPD-CBT consists of seven weekly 20 min sessions and a 1-month follow-up session. Assessments will be conducted at baseline, 13 weeks post randomisation (primary endpoint for between-group comparison), with an additional 25 weeks post randomisation. The waitlist control group will receive GPD-CBT after the 13-week assessment.Ethics and dissemination This study has been approved by the Ethics Review Committees of Chiba University and the University of Tokyo. We will disseminate results through academic conference presentations and peer-reviewed journal publications. If the GPD-CBT intervention proves efficacious, we will promote wider implementation in Japan through the development of training programmes for mental health professionals and key stakeholders.Trial registration numbers jRCT1032250421 ( https://jrct.mhlw.go.jp/latest-detail/jRCT1032250421) and jRCT1030250422 (https://jrct.mhlw.go.jp/latest-detail/jRCT1030250422) registered on 9 October 2025.",
  "authors": [
    {
      "affiliations": [
        "Department of Life Sciences, The University of Tokyo, Tokyo, Japan",
        "Research Center for Child Mental Development, Chiba University, Chiba, Japan"
      ],
      "name": "Sho Okawa"
    },
    {
      "affiliations": [
        "Department of Clinical Psychology and Experimental Psychopathology, Institute of Psychology, University of Göttingen, Göttingen, Germany"
      ],
      "name": "Simon E Blackwell"
    },
    {
      "affiliations": [
        "Nuffield Department of Population Health, University of Oxford, Oxford, UK"
      ],
      "name": "Mara Violato"
    },
    {
      "affiliations": [
        "Department of Experimental Psychology, University of Oxford, Oxford, UK",
        "Department of Psychiatry, University of Oxford, Oxford, UK"
      ],
      "name": "Cathy Creswell"
    },
    {
      "affiliations": [
        "Faculty of Psychology, Doshisha University, Kyoto, Japan"
      ],
      "name": "Shin-ichi Ishikawa"
    },
    {
      "affiliations": [
        "Department of Social Medicine, National Center for Child Health and Development, Tokyo, Japan"
      ],
      "name": "Erika Obikane"
    },
    {
      "affiliations": [
        "Faculty of Education, University of Miyazaki, Miyazaki, Japan"
      ],
      "name": "Takahito Takahashi"
    },
    {
      "affiliations": [
        "Center for Research on Counseling and Support Services, The University of Tokyo, Tokyo, Japan"
      ],
      "name": "Honami Arai"
    },
    {
      "affiliations": [
        "Research Center for Child Mental Development, Chiba University, Chiba, Japan",
        "Department of Psychiatric Nursing, Faculty of Nursing, Toho University, Tokyo, Japan"
      ],
      "name": "Hideki Nakamura"
    },
    {
      "affiliations": [
        "Division of Lifecourse Epidemiology, Integrated Center for Women's Health, National Center for Child Health and Development, Tokyo, Japan"
      ],
      "name": "Kazue Ishitsuka"
    },
    {
      "affiliations": [
        "Research Center for Child Mental Development, Chiba University, Chiba, Japan",
        "Department of Cognitive Behavioral Physiology, Graduate School of Medicine, Chiba University, Chiba, Japan"
      ],
      "name": "Eiji Shimizu"
    },
    {
      "affiliations": [
        "Department of Child Psychiatry, Chiba University Hospital, Chiba, Japan"
      ],
      "name": "Tsuyoshi Sasaki"
    }
  ],
  "title": "Bayesian randomised controlled trial of guided parent-delivered cognitive behavioural therapy for children with anxiety disorders via remote sessions in Japan: a study protocol",
  "uid": "83cb6ed7-db41-5697-b21f-e95bdf719bb6"
}