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Article History

Received: 5 September 2025

Accepted: 11 February 2026

First Online: 20 February 2026

Declarations

:

: Ethical approval was obtained from the relevant authorities in each participating country: Australia (AIHW HREC EO2021/1/1233; NSW PHSREC 2020/ETH02273), Denmark (Danish Data Protection Agency; Act no. 1338 of 1 September 2020), the Netherlands (Statistics Netherlands project agreement 9205), Norway (Regional Ethics Committee in Western Norway 2020/75421), Sweden (Swedish Ethical Review Authority 2020-06540), the United Kingdom (THIN Scientific Review Committee 17THIN102), and the United States (SUNY Upstate Medical University IRB 1933232-2). Informed consent was waived in all countries due to the use of de-identified or pseudonymized registry data.Not applicable, as the study used de-identified registry data and did not involve direct patient contact.

: Not applicable.

: HL reports receiving grants from TAKEDA and Shire Pharmaceuticals; personal fees from and serving as a speaker for Medice, Shire/Takeda Pharmaceuticals and Evolan Pharma AB; all outside the submitted work. HL is editor-in-chief of JCPP Advances. SVF reports personal fees and travel expenses from Mentavi/ADHD Online, Axsome, Ironshore/Collegium, KemPharm/Corium, Noven, Supernus, Sandoz, Tris and Medice; has a US patent (via his institution) for the use of sodium-hydrogen exchange inhibitors in the treatment of ADHD (US20130217707 A1); receives royalties from books published by Guilford Press (Straight Talk about Your Child's Mental Health), Oxford University Press (Schizophrenia: The Facts), and Elsevier (ADHD: Non-Pharmacologic Interventions); and is program director of and . KKCM reports grants from the C W Maplethorpe Fellowship, the National Institute for Health and Care Research, Innovation and Technology Commission of the Hong Kong Special Administration Region Government, and Hong Kong Research Grant Council; and personal fees from IQVIA, all outside the submitted work. ICKW reports research funding from Amgen and GSK, the Hong Kong Research Grants Council, the Hong Kong Health and Medical Research Fund, the National Institute for Health Research in England, the European Commission, and the National Health and Medical Research Council in Australia, consulting fees from IQVIA and World Health Organisation, outside of the submitted work. He is a non-executive director of Jacobson Medical, Advance Data Analytics for Medical Science (ADAMS) Limited in Hong Kong and OCUS Innovation Limited (HK, Ireland and UK); a former director of Therakind in England and Asia Medicine Regulatory Affairs (AMERA) Services Limited in Hong Kong. ZC received speaker fees from Takeda Pharmaceuticals, outside the submitted work. All other authors declare no competing interests. ASCY reports grant from the University College London Hospitals NIHR Biomedical Research Centre, College of Mental Health Pharmacy, and UK Turing Scheme.