{
  "abstract": "Background Poor persistence and adherence to attention-deficit/hyperactivity disorder (ADHD) medication is a significant barrier to effective long-term care, particularly during adolescence, yet age-specific and sex-specific trajectories remain poorly characterised.Objective To characterise medication initiation, discontinuation and long-term adherence patterns for children and adolescents diagnosed with ADHD in a real-world setting.Methods A nationwide retrospective cohort study, including 8961 children and adolescents (aged <18 years) with a new ADHD diagnosis in child and adolescent mental health services between 1 January 2010 and 31 December 2012, with follow-up until 31 December 2021. Main outcomes were medication initiation rates; time to first medication discontinuation, analysed using Kaplan-Meier estimates and restricted mean survival time at 1 year and longitudinal adherence, measured by the proportion of days covered over 9 years.Findings Of the 8961 individuals in the cohort (mean age at diagnosis, 12 years; 69% male), 6661 (74.3%) initiated medication, with a median time from diagnosis to initiation of 106 days (IQR 17–231); 55% initiated within 90 days. Discontinuation increased significantly with age; adolescents aged 15–17 years remained on treatment for 31.9 fewer days (95% CI −40.8 to −23.1; p<0.001) in the first year compared with children aged 5–11 years. Females also discontinued significantly earlier than males (difference −13.2 days; 95% CI −19.8 to −6.5; p<0.001). Longitudinal analysis confirmed that older age at initiation and female sex were associated with a significantly steeper decline in medication coverage over time.Conclusions Discontinuation and low adherence to ADHD medication were common and increased substantially through adolescence, with females at higher risk of early cessation.Clinical implications Late adolescence warrants closer clinical monitoring and shared decision-making to support appropriate treatment continuation or well-informed discontinuation, particularly for older adolescents and females. Integrating structured transition planning and attention to sex-specific barriers may help reduce avoidable non-adherence during this high-risk period.",
  "authors": [
    {
      "affiliations": [
        "Centre for Population Health, Research Department, Division of Mental Health, Haukeland University Hospital, Bergen, Norway",
        "Developmental EPI (Evidence synthesis, Prediction, Implementation) lab, Centre for Innovation in Mental Health, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, UK",
        "School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden",
        "Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden"
      ],
      "name": "Miguel Garcia-Argibay"
    },
    {
      "affiliations": [
        "Centre for Population Health, Research Department, Division of Mental Health, Haukeland University Hospital, Bergen, Norway",
        "Centre for Medical Ethics, University of Oslo, Oslo, Norway"
      ],
      "name": "Tore Hofstad"
    },
    {
      "affiliations": [
        "Centre for Population Health, Research Department, Division of Mental Health, Haukeland University Hospital, Bergen, Norway",
        "Department of Clinical Medicine, University of Bergen, Bergen, Norway"
      ],
      "name": "Ingvar Bjelland"
    },
    {
      "affiliations": [
        "Developmental EPI (Evidence synthesis, Prediction, Implementation) lab, Centre for Innovation in Mental Health, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, UK",
        "Hampshire and Isle of Wight NHS Foundation Trust, Southampton, UK",
        "Clinical and Experimental Sciences (CNS and Psychiatry), Faculty of Medicine, University of Southampton, Southampton, UK",
        "Hassenfeld Children’s Hospital at NYU Langone, New York University Child Study Center, New York, New York, USA",
        "DiMePRe-J-Department of Precision and Regenerative Medicine-Jonic Area, University of Bari \"Aldo Moro\", Bari, Italy"
      ],
      "name": "Samuele Cortese"
    },
    {
      "affiliations": [
        "Centre for Population Health, Research Department, Division of Mental Health, Haukeland University Hospital, Bergen, Norway",
        "Centre for Work and Mental Health, Nordland Hospital Trust, Bodø, Norway",
        "Department of Community Medicine, The Arctic University of Norway, Tromsø, Norway",
        "Division for Health Services, Norwegian Institute of Public Health, Oslo, Norway"
      ],
      "name": "Arnstein Mykletun"
    }
  ],
  "title": "ADHD medication discontinuation and non-adherence: a Norwegian population-based register study",
  "uid": "3b65f0df-2749-520b-822e-d9659b03ab1f"
}