{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T17:05:40Z","timestamp":1774285540703,"version":"3.50.1"},"reference-count":47,"publisher":"BMJ","issue":"3","license":[{"start":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T00:00:00Z","timestamp":1774224000000},"content-version":"unspecified","delay-in-days":22,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"JSPS KAKENHI","award":["23K12891"],"award-info":[{"award-number":["23K12891"]}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2026,3,5]]},"published-print":{"date-parts":[[2026,3]]},"abstract":"\n Introduction<\/jats:title>\n 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\u2019s efficacy and cost-effectiveness in Japanese samples and explore potential cultural adaptations of the programme.<\/jats:p>\n <\/jats:sec>\n \n Method and analysis<\/jats:title>\n 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\u2013170 families, depending on the results of sequential Bayesian analyses. GPD-CBT consists of seven\u2009weekly 20\u2009min 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.<\/jats:p>\n <\/jats:sec>\n \n Ethics and dissemination<\/jats:title>\n 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.<\/jats:p>\n <\/jats:sec>\n \n Trial registration numbers<\/jats:title>\n \n jRCT1032250421 (\n https:\/\/jrct.mhlw.go.jp\/latest-detail\/jRCT1032250421<\/jats:ext-link>\n ) and jRCT1030250422 (\n https:\/\/jrct.mhlw.go.jp\/latest-detail\/jRCT1030250422<\/jats:ext-link>\n ) registered on 9 October 2025.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1136\/bmjopen-2025-114705","type":"journal-article","created":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T16:20:35Z","timestamp":1774282835000},"page":"e114705","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"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"],"prefix":"10.1136","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8428-5960","authenticated-orcid":false,"given":"Sho","family":"Okawa","sequence":"first","affiliation":[{"name":"Department of Life Sciences, The University of Tokyo, Tokyo, Japan"},{"name":"Research Center for Child Mental Development, Chiba University, Chiba, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Simon E","family":"Blackwell","sequence":"additional","affiliation":[{"name":"Department of Clinical Psychology and Experimental Psychopathology, Institute of Psychology, University of G\u00f6ttingen, G\u00f6ttingen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mara","family":"Violato","sequence":"additional","affiliation":[{"name":"Nuffield Department of Population Health, University of Oxford, Oxford, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cathy","family":"Creswell","sequence":"additional","affiliation":[{"name":"Department of Experimental Psychology, University of Oxford, Oxford, UK"},{"name":"Department of Psychiatry, University of Oxford, Oxford, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shin-ichi","family":"Ishikawa","sequence":"additional","affiliation":[{"name":"Faculty of Psychology, Doshisha University, Kyoto, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erika","family":"Obikane","sequence":"additional","affiliation":[{"name":"Department of Social Medicine, National Center for Child Health and Development, Tokyo, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takahito","family":"Takahashi","sequence":"additional","affiliation":[{"name":"Faculty of Education, University of Miyazaki, Miyazaki, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Honami","family":"Arai","sequence":"additional","affiliation":[{"name":"Center for Research on Counseling and Support Services, The University of Tokyo, Tokyo, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hideki","family":"Nakamura","sequence":"additional","affiliation":[{"name":"Research Center for Child Mental Development, Chiba University, Chiba, Japan"},{"name":"Department of Psychiatric Nursing, Faculty of Nursing, Toho University, Tokyo, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kazue","family":"Ishitsuka","sequence":"additional","affiliation":[{"name":"Division of Lifecourse Epidemiology, Integrated Center for Women's Health, National Center for Child Health and Development, Tokyo, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6741-9338","authenticated-orcid":false,"given":"Eiji","family":"Shimizu","sequence":"additional","affiliation":[{"name":"Research Center for Child Mental Development, Chiba University, Chiba, Japan"},{"name":"Department of Cognitive Behavioral Physiology, Graduate School of Medicine, Chiba University, Chiba, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tsuyoshi","family":"Sasaki","sequence":"additional","affiliation":[{"name":"Department of Child Psychiatry, Chiba University Hospital, Chiba, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2026,3,23]]},"reference":[{"key":"2026032309201695000_16.3.e114705.1","doi-asserted-by":"publisher","DOI":"10.1038\/s41380-021-01161-7"},{"key":"2026032309201695000_16.3.e114705.2","doi-asserted-by":"crossref","DOI":"10.1002\/jcv2.12149","article-title":"The multifaceted consequences and economic costs of child anxiety problems: A systematic review and meta-analysis","volume":"3","author":"Pollard","year":"2023","journal-title":"JCPP Adv"},{"key":"2026032309201695000_16.3.e114705.3","article-title":"Cognitive behavioural therapy for anxiety disorders in children and adolescents","volume":"11","author":"James","year":"2020","journal-title":"Cochrane Database Syst Rev"},{"key":"2026032309201695000_16.3.e114705.4","doi-asserted-by":"publisher","DOI":"10.1007\/S00787-019-01469-4\/FIGURES\/5"},{"key":"2026032309201695000_16.3.e114705.5","doi-asserted-by":"crossref","first-page":"649","DOI":"10.1007\/s00787-019-01388-4","article-title":"Seeking and accessing professional support for child anxiety in a community sample","volume":"29","author":"Reardon","year":"2020","journal-title":"Eur Child Adolesc Psychiatry"},{"key":"2026032309201695000_16.3.e114705.6","doi-asserted-by":"publisher","DOI":"10.1192\/bjp.bp.113.126698"},{"key":"2026032309201695000_16.3.e114705.7","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1016\/S2215-0366(17)30149-9","article-title":"Clinical outcomes and cost-effectiveness of brief guided parent-delivered cognitive behavioural therapy and solution-focused brief therapy for treatment of childhood anxiety disorders: a randomised controlled trial","volume":"4","author":"Creswell","year":"2017","journal-title":"Lancet Psychiatry"},{"key":"2026032309201695000_16.3.e114705.8","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/S2215-0366(23)00429-7","article-title":"Digitally augmented, parent-led CBT versus treatment as usual for child anxiety problems in child mental health services in England and Northern Ireland: a pragmatic, non-inferiority, clinical effectiveness and cost-effectiveness randomised controlled trial","volume":"11","author":"Creswell","year":"2024","journal-title":"Lancet Psychiatry"},{"key":"2026032309201695000_16.3.e114705.9","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1017\/S1352465822000704","article-title":"Guided parent-delivered cognitive behavioural therapy for Japanese children and parents: a single-arm uncontrolled study","volume":"51","author":"Okawa","year":"2023","journal-title":"Behav Cogn Psychother"},{"key":"2026032309201695000_16.3.e114705.10","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2022-068855","article-title":"Randomised controlled trial of cultural-adapted and programme-adopted cognitive behavioural therapy for children and adolescents\u2019 anxiety in Japan: protocol for a Multi-, Inter-, and Cross-cultural Clinical Child Study (MIXCS)","volume":"13","author":"Takashina","year":"2023","journal-title":"BMJ Open"},{"key":"2026032309201695000_16.3.e114705.11","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1038\/s44220-025-00391-w","article-title":"Transforming the evidence landscape in mental health with platform trials","volume":"3","author":"Gold","year":"2025","journal-title":"Nat Mental Health"},{"key":"2026032309201695000_16.3.e114705.12","doi-asserted-by":"crossref","DOI":"10.3389\/fdgth.2022.823977","article-title":"Appropriate controls for digital therapeutic clinical trials: A narrative review of control conditions in clinical trials of digital therapeutics (DTx) deploying psychosocial, cognitive, or behavioral content","volume":"4","author":"Lutz","year":"2022","journal-title":"Front Digit Health"},{"key":"2026032309201695000_16.3.e114705.13","doi-asserted-by":"crossref","DOI":"10.1186\/s13012-022-01245-0","article-title":"The updated Consolidated Framework for Implementation Research based on user feedback","volume":"17","author":"Damschroder","year":"2022","journal-title":"Implement Sci"},{"key":"2026032309201695000_16.3.e114705.14","doi-asserted-by":"publisher","DOI":"10.1186\/s13012-019-0898-y"},{"key":"2026032309201695000_16.3.e114705.15","doi-asserted-by":"publisher","DOI":"10.1037\/met0000061"},{"key":"2026032309201695000_16.3.e114705.16","doi-asserted-by":"crossref","first-page":"1222","DOI":"10.1177\/2167702619858071","article-title":"Introducing the Leapfrog Design: A Simple Bayesian Adaptive Rolling Trial Design for Accelerated Treatment Development and Optimization","volume":"7","author":"Blackwell","year":"2019","journal-title":"Clin Psychol Sci"},{"key":"2026032309201695000_16.3.e114705.17","doi-asserted-by":"crossref","first-page":"6113","DOI":"10.1017\/S0033291722003294","article-title":"Demonstration of a \u201cleapfrog\u201d randomized controlled trial as a method to accelerate the development and optimization of psychological interventions","volume":"53","author":"Blackwell","year":"2023","journal-title":"Psychol Med"},{"key":"2026032309201695000_16.3.e114705.18","unstructured":"Goodrich B , Gabry J , Ali I , et al . Rstanarm: bayesian applied regression modeling via stan. 2024."},{"key":"2026032309201695000_16.3.e114705.19","doi-asserted-by":"crossref","first-page":"1827","DOI":"10.1007\/s00406-024-01926-5","article-title":"Intermittent theta burst stimulation in adolescents and young adults with depressive disorders: protocol of a randomized, sham-controlled study with a sequential Bayesian design for adaptive trials","volume":"275","author":"Burkhardt","year":"2025","journal-title":"Eur Arch Psychiatry Clin Neurosci"},{"key":"2026032309201695000_16.3.e114705.20","doi-asserted-by":"publisher","DOI":"10.1177\/1049732315617444"},{"key":"2026032309201695000_16.3.e114705.21","doi-asserted-by":"crossref","unstructured":"Silverman WK , Albano AM . The Anxiety Disorders Interview Schedule for DSM-5, Child and Parent Versions. Psychological Corporation, 2024.","DOI":"10.1093\/med-psych\/9780199348343.003.0001"},{"key":"2026032309201695000_16.3.e114705.22","doi-asserted-by":"publisher","DOI":"10.1016\/S0005-7967(99)00130-8"},{"key":"2026032309201695000_16.3.e114705.23","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1080\/15374416.2013.817311","article-title":"The child anxiety impact scale: examining parent- and child-reported impairment in child anxiety disorders","volume":"43","author":"Langley","year":"2014","journal-title":"J Clin Child Adolesc Psychol"},{"key":"2026032309201695000_16.3.e114705.24","doi-asserted-by":"crossref","first-page":"11450","DOI":"10.1007\/s12144-021-02437-5","article-title":"Preliminary examination of reliability and validity of the Japanese child anxiety impact scale-parent version in Japanese community sample","volume":"42","author":"Okawa","year":"2023","journal-title":"Curr Psychol"},{"key":"2026032309201695000_16.3.e114705.25","doi-asserted-by":"crossref","first-page":"5113","DOI":"10.3390\/ijerph110505113","article-title":"Does the absence of a supportive family environment influence the outcome of a universal intervention for the prevention of depression?","volume":"11","author":"Spence","year":"2014","journal-title":"Int J Environ Res Public Health"},{"key":"2026032309201695000_16.3.e114705.26","doi-asserted-by":"crossref","first-page":"64","DOI":"10.14389\/jsad.10.1_64","article-title":"Development, reliability, and validity of the Japanese short version of the Spence Children\u2019s Anxiety Scale for adolescents","volume":"10","author":"Ishikawa","year":"2018","journal-title":"Anxiety Disord Res"},{"key":"2026032309201695000_16.3.e114705.27","doi-asserted-by":"publisher","DOI":"10.1001\/archinte.166.10.1092"},{"key":"2026032309201695000_16.3.e114705.28","doi-asserted-by":"crossref","DOI":"10.3389\/fpsyg.2018.01741","article-title":"Factorial Validity and Invariance of the 7-Item Generalized Anxiety Disorder Scale (GAD-7) Among Populations With and Without Self-Reported Psychiatric Diagnostic Status","volume":"9","author":"Doi","year":"2018","journal-title":"Front Psychol"},{"key":"2026032309201695000_16.3.e114705.29","unstructured":"Muramatsu K , Muramatsu Y , Miyaoka H , et al . Validation and utility of a japanese version of the gad-7, 20th world congress on psychosomatic medicine. 2009."},{"key":"2026032309201695000_16.3.e114705.30","unstructured":"Edwards SL , Rapee RM , Kennedy S . Psychometric properties of a parent-report measure of overprotection in preschool aged children. 2008."},{"key":"2026032309201695000_16.3.e114705.31","doi-asserted-by":"crossref","unstructured":"Okawa S , Rapee RM , Takahashi T , et al . Psychometric Properties of the Japanese Translation of the Parent Overprotection Measure for Mother and Father Reports. Child Psychiatry Hum Dev 2024. doi:10.1007\/s10578-024-01753-8","DOI":"10.1007\/s10578-024-01753-8"},{"key":"2026032309201695000_16.3.e114705.32","doi-asserted-by":"publisher","DOI":"10.1207\/s15374424jccp1802_8"},{"key":"2026032309201695000_16.3.e114705.33","first-page":"23","article-title":"Reliability and validity of the Japanese version of the Parenting Sense of Competence Scale","volume":"11","author":"Abe","year":"2009","journal-title":"J North Jpn Acad Nurs Sci"},{"key":"2026032309201695000_16.3.e114705.34","doi-asserted-by":"publisher","DOI":"10.1023\/A:1015630930326"},{"key":"2026032309201695000_16.3.e114705.35","doi-asserted-by":"crossref","first-page":"510","DOI":"10.1111\/j.1464-0597.2008.00333.x","article-title":"Work engagement in Japan: Validation of the Japanese version of the Utrecht Work Engagement Scale","volume":"57","author":"Shimazu","year":"2008","journal-title":"Appl Psychol"},{"key":"2026032309201695000_16.3.e114705.36","doi-asserted-by":"publisher","DOI":"10.1016\/S0005-7916(00)00012-4"},{"key":"2026032309201695000_16.3.e114705.37","doi-asserted-by":"crossref","DOI":"10.2196\/24332","article-title":"Implementation Outcome Scales for Digital Mental Health (iOSDMH): Scale Development and Cross-sectional Study","volume":"5","author":"Sasaki","year":"2021","journal-title":"JMIR Form Res"},{"key":"2026032309201695000_16.3.e114705.38","doi-asserted-by":"publisher","DOI":"10.1007\/s11136-011-9903-x"},{"key":"2026032309201695000_16.3.e114705.39","doi-asserted-by":"publisher","DOI":"10.1016\/j.jval.2016.03.1834"},{"key":"2026032309201695000_16.3.e114705.40","doi-asserted-by":"publisher","DOI":"10.1007\/s11136-010-9648-y"},{"key":"2026032309201695000_16.3.e114705.41","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1177\/0272989X211001859","article-title":"Valuation Survey of EQ-5D-Y Based on the International Common Protocol: Development of a Value Set in Japan","volume":"41","author":"Shiroiwa","year":"2021","journal-title":"Med Decis Making"},{"key":"2026032309201695000_16.3.e114705.42","doi-asserted-by":"publisher","DOI":"10.2165\/11599120-000000000-00000"},{"key":"2026032309201695000_16.3.e114705.43","doi-asserted-by":"publisher","DOI":"10.1177\/1359104599004004003"},{"key":"2026032309201695000_16.3.e114705.44","unstructured":"Law D , Jacob J . Goals and Goal Based Outcomes (GBOs). CAMHS Press, 2015."},{"key":"2026032309201695000_16.3.e114705.45","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.jval.2019.10.005","article-title":"Formal Implementation of Cost-Effectiveness Evaluations in Japan: A Unique Health Technology Assessment System","volume":"23","author":"Hasegawa","year":"2020","journal-title":"Value Health"},{"key":"2026032309201695000_16.3.e114705.46","doi-asserted-by":"crossref","unstructured":"Fenwick E , Marshall DA , Levy AR , et al . Using and interpreting cost-effectiveness acceptability curves: an example using data from a trial of management strategies for atrial fibrillation. BMC Health Serv Res 2006;6. doi:10.1186\/1472-6963-6-52","DOI":"10.1186\/1472-6963-6-52"},{"key":"2026032309201695000_16.3.e114705.47","doi-asserted-by":"publisher","DOI":"10.1080\/2159676X.2019.1628806"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2025-114705","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T16:20:40Z","timestamp":1774282840000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2025-114705"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3]]},"references-count":47,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,3,23]]},"published-print":{"date-parts":[[2026,3]]}},"alternative-id":["10.1136\/bmjopen-2025-114705"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2025-114705","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3]]}}}