Title {1}	Efficacy of behavioural parent training on attachment security in children with attention deficit hyperactivity disorder: a randomised controlled trial
Trial registration {2a and 2b}	UMIN000038693 November 9, 2019. UMIN website https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000043967
Protocol version {3}	Version 7 of 04–12-2023
Funding {4}	This study was supported in part by the Japan Agency for Medical Research and Development (AMED) under grant number JP21gk0110035h0003 to AI-T, MHLW under grant number JP21GC1020 to AI-T, and the Japan Society for the Promotion of Science, KAKENHI under Grant-in-Aid for Scientific Research (C) No. 23K07050 to AI-T.
Author details {5a}	Ayaka Ishii-Takahashi1,2, Junko Hamada2, Rio Yamaguchi2, Takuya Kawahara3, Takayo Mukai4, Sudre Gustavo5, Philip Shaw5, Sato Ashida6, Laura Koehly5, Kengo Tsujimoto7, Yuzu Yoshimaru1,2, Yukiko Kano2 1Department of Developmental Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan 2Department of Child Psychiatry, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan 3Clinical Research Promotion Center, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan 4Department of Psychology, The University of the Sacred Heart, Shibuya, Tokyo, Japan 5Neurobehavioral Clinical Research Section, Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA 6Department of Community and Behavioral Health, The University of Iowa College of Public Health, Iowa City, IA, USA 7Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan *Corresponding author: E-mail: ayayak-tky@umin.ac.jp (A.I-T.)
Name and contact information for the trial sponsor {5b}	Investigator-initiated clinical trial; Ayaka Ishii-Takahashi (principal investigator) ayayak-tky@umin.ac.jp (A.I-T.)
Role of sponsor {5c}	This is an investigator-initiated clinical trial. Therefore, the funders played no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.