{
  "abstract": "Background Comorbid attention-deficit/hyperactivity disorder (ADHD) increases the burden in bipolar disorder (BD). Concerns about the risk/benefit balance of ADHD treatment have been raised.Objective This study aimed to investigate the association between hospital admissions and add-on ADHD medications to antipsychotics and/or mood-stabilisers (APs/MSs) compared with AP/MS alone in BD.Methods Individuals with BD prescribed ADHD medications in Sweden during 2006–2021 were identified from national registers of inpatient care, specialised outpatient care, sickness absence and disability pension. ADHD treatment was defined as stimulants (mostly methylphenidate and lisdexamfetamine, rarely amphetamine, dexamphetamine) and non-stimulants (atomoxetine, modafinil). Add-on ADHD treatment to concomitant AP/MS was compared with treatment periods with AP/MS without ADHD treatment, using within-individual models where individuals acted as their own control. Adjusted HRs (aHRs) and CIs (95% CIs) were calculated for the primary outcome of psychiatric hospitalisation, and for the secondary outcomes: substance-use-related, somatic or mania-related hospitalisations, and all-cause hospitalisation/mortality.Results Altogether, 17 971 individuals (mean age=32.0±11.6 years, males=37.6%, ADHD=88.9%, follow-up=8.9±4.4 years) with BD who used any ADHD treatment were included. compared with the use of AP/MS alone, add-on stimulant use was related to a lower risk of psychiatric hospitalisations (aHR=0.89, 95% CI 0.85 to 0.93), substance-related hospitalisations (aHR=0.75, 95% CI 0.70 to 0.81) and all-cause hospitalisations/mortality (aHR=0.90, 95% CI 0.87 to 0.93), but was not associated with increased risk for somatic (aHR=1.00, 95% CI 0.90 to 1.12) or mania-related hospitalisations (aHR=0.93, 95% CI 0.72 to 1.20). Of commonly used specific ADHD medications, add-on lisdexamfetamine (aHR=0.81, 95% CI 0.75 to 0.87) and methylphenidate (aHR=0.92, 95% CI 0.88 to 0.97) were associated with decreased risk of psychiatric hospitalisations while add-on atomoxetine was not. Findings on substance-use-related hospitalisations were significant only for stimulants, specifically lisdexamfetamine (aHR=0.70, 95% CI 0.61 to 0.79) and methylphenidate (aHR=0.80, 95% CI 0.74 to 0.86).Conclusions Among individuals with BD who received ADHD medications, add-on lisdexamfetamine and methylphenidate were associated with lower risks of psychiatric and substance-use-related hospital admissions, compared with AP/MS use alone. No significant association was found between ADHD medication use and mania-related hospitalisations or somatic admissions when these medications were used together with AP/MS. Larger samples are needed to reach adequate statistical power and conclusive findings on atomoxetine, dexamfetamine and modafinil.Clinical implications The findings of this study suggested that the treatment of comorbid ADHD could be considered after adequate mood-stabilisation in patients with BD.",
  "authors": [
    {
      "affiliations": [
        "Department of Child and Adolescent Psychiatry, Sahlgrenska University Hospital, Gothenburg, Sweden"
      ],
      "name": "Cagatay Ermis"
    },
    {
      "affiliations": [
        "Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Kuopio, Finland",
        "Department of Clinical Neuroscience, Division of Insurance Medicine, Karolinska Institutet, Stockholm, Sweden"
      ],
      "name": "Antti Tanskanen"
    },
    {
      "affiliations": [
        "Ottawa Hospital Research Institute (OHRI), Clinical Epidemiology Program, SCIENCES Lab, University of Ottawa, Ottawa, Ontario, Canada",
        "Department of Pharmacy, Mental Health University Institute of Quebec, Québec City, Quebec, Canada"
      ],
      "name": "Olivier Corbeil"
    },
    {
      "affiliations": [
        "Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Kuopio, Finland",
        "Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Stockholm County, Sweden"
      ],
      "name": "Johannes Lieslehto"
    },
    {
      "affiliations": [
        "Bipolar and Depressive Disorders Unit, Institute of Neuroscience, Hospital Clinic, IDIBAPS, CIBERSAM, University of Barcelona, Barcelona, Spain"
      ],
      "name": "Eduard Vieta"
    },
    {
      "affiliations": [
        "Department of Child and Adolescent Psychiatry, Charité - Universitätsmedizin Berlin, Berlin, Germany",
        "Department of Psychiatry and Molecular Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, USA"
      ],
      "name": "Christoph U Correll"
    },
    {
      "affiliations": [
        "Department of Clinical Neuroscience, Division of Insurance Medicine, Karolinska Institutet, Stockholm, Sweden"
      ],
      "name": "Ellenor Mittendorfer-Rutz"
    },
    {
      "affiliations": [
        "Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Kuopio, Finland",
        "Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Stockholm County, Sweden"
      ],
      "name": "Jari Tiihonen"
    },
    {
      "affiliations": [
        "Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Kuopio, Finland",
        "Department of Clinical Neuroscience, Division of Insurance Medicine, Karolinska Institutet, Stockholm, Sweden"
      ],
      "name": "Heidi Taipale"
    }
  ],
  "title": "Reduced risk of cause-specific hospitalisations and all-cause hospitalisation/mortality during treatment with attention-deficit/hyperactivity disorder medications in the course of bipolar disorder: a Swedish registry-based within-subject cohort study",
  "uid": "8fb2f2a5-b3bd-5b09-abd0-859dfe4e2aff"
}