Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong Special Administrative Region, China.
School of Population Health, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia.
Department of Psychiatry, Interdisciplinary Center of Psychopathology and Emotion Regulation, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.
Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, NY, USA.
National Centre for Register-based Research, Aarhus University, Aarhus, Denmark; Center for Child and Adolescent Psychiatry, Mental Health Services of the Capital Region, Glostrup, Denmark; Institute of Clinical Medicine, University of Copenhagen, København, Denmark.
Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
Norton College of Medicine, SUNY Upstate Medical University, Syracuse, NY, USA.
Department of Biomedicine, University of Bergen, Bergen, Norway; Bergen Center of Brain Plasticity, Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.
Department of Psychiatry, Interdisciplinary Center of Psychopathology and Emotion Regulation, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.
Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong Special Administrative Region, China.
Centre of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong Special Administrative Region, China; Research Department of Practice and Policy, School of Pharmacy, University College London, London, UK; Centre for Medicines Optimisation Research and Education, University College London Hospitals NHS Foundation Trust, London, UK; Laboratory of Data Discovery for Health, Hong Kong Special Administrative Region, China.
School of Population Health, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia.
School of Population Health, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia.
Center for Child and Adolescent Psychiatry, Mental Health Services of the Capital Region, Glostrup, Denmark.
Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.
National Centre for Register-based Research, Aarhus University, Aarhus, Denmark; Centre for Integrated Register-based Research, Aarhus University, Aarhus, Denmark.
Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong Special Administrative Region, China; Research Department of Practice and Policy, School of Pharmacy, University College London, London, UK; Laboratory of Data Discovery for Health, Hong Kong Special Administrative Region, China; Aston Pharmacy School, Aston University, Birmingham, UK.
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
School of Population Health, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia; Centre of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; Department of Health Promotion, Norwegian Institute of Public Health, Bergen, Norway.
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
BACKGROUND: Although often intended for long-term treatment, discontinuation of medication for ADHD is common. However, cross-national estimates of discontinuation are missing due to the absence of standardised measures. The aim of this study was to determine the rate of ADHD treatment discontinuation across the lifespan and to describe similarities and differences across countries to guide clinical practice.
METHODS: We did a retrospective, observational study using population-based databases from eight countries and one Special Administrative Region (Australia, Denmark, Hong Kong, Iceland, the Netherlands, Norway, Sweden, the UK, and the USA). We used a common analytical protocol approach and extracted prescription data to identify new users of ADHD medication. Eligible individuals were aged 3 years or older who had initiated ADHD medication between 2010 and 2020. We estimated treatment discontinuation and persistence in the 5 years after treatment initiation, stratified by age at initiation (children [age 4-11 years], adolescents [age 12-17 years], young adults [age 18-24 years], and adults [age ≥25 years]) and sex. Ethnicity data were not available.
FINDINGS: 1 229 972 individuals (735 503 [60%] males, 494 469 females [40%]; median age 8-21 years) were included in the study. Across countries, treatment discontinuation 1-5 years after initiation was lowest in children, and highest in young adults and adolescents. Within 1 year of initiation, 65% (95% CI 60-70) of children, 47% (43-51) of adolescents, 39% (36-42) of young adults, and 48% (44-52) of adults remained on treatment. The proportion of patients discontinuing was highest between age 18 and 19 years. Treatment persistence for up to 5 years was higher across countries when accounting for reinitiation of medication; at 5 years of follow-up, 50-60% of children and 30-40% of adolescents and adults were covered by treatment in most countries. Patterns were similar across sex.
INTERPRETATION: Early medication discontinuation is prevalent in ADHD treatment, particularly among young adults. Although reinitiation of medication is common, treatment persistence in adolescents and young adults is lower than expected based on previous estimates of ADHD symptom persistence in these age groups. This study highlights the scope of medication treatment discontinuation and persistence in ADHD across the lifespan and provides new knowledge about long-term ADHD medication use.
FUNDING: European Union Horizon 2020 Research and Innovation Programme.
Elsevier, 2024. Vol. 11, no 1, p. 16-26