The prevalence and effects of adult attention-deficit/hyperactivity disorder (ADHD) on the performance of workers: results from the WHO World Mental Health Survey Initiative
- R de Graaf1,
- R C Kessler2,
- J Fayyad3,
- M ten Have1,
- J Alonso4,
- M Angermeyer5,
- G Borges6,
- K Demyttenaere7,
- I Gasquet8,
- G de Girolamo9,
- J M Haro10,
- R Jin2,
- E G Karam3,
- J Ormel11,
- J Posada-Villa12
- 1Netherlands Institute of Mental Health and Addiction, Utrecht, The Netherlands
- 2Harvard Medical School, Department of Health Care Policy, Boston, MA, USA
- 3Institute for Development, Research, Advocacy and Applied Care (IDRAAC), Department of Psychiatry and Clinical Psychology, St. George Hospital University Medical Center and Faculty of Medicine, Balamand University, Beirut, Lebanon
- 4Health Services Research Unit, Institut Municipal d’Investigació Mèdica (IMIM), Barcelona, CIBER en Epidemiologia y Salud Publica (CIBERESP), Spain
- 5Department of Psychiatry, University of Leipzig, Germany
- 6Instituto Nacional de Psiquiatria and Universidad Autónoma Metropolitana-Xochimilco, Calzada, Mexico City, Mexico
- 7Department of Neurosciences and Psychiatry, University Hospitals Gasthuisberg, University of Leuven, Leuven, Belgium
- 8Hôpitaux de Paris, Paris, France
- 9Health Care Research Agency, Emilia-Romanga Region, Bologna, Italy
- 10Sant Joan de Déu-SSM, Fundació Sant Joan de Déu, Sant Boi de Llobregat, Barcelona, Spain
- 11Department of Psychiatry and Department of Epidemiology and Bioinformatics, University Medical Center Groningen, Graduate School of Behavioural and Cognitive Neurosciences and Graduate School for Experimental Psychopathology, University of Groningen, The Netherlands
- 12Medico Psiquiatra, U. Javerina, Centro Medico de la Sabana, Bogota, Colombia
- Dr Ron de Graaf, Netherlands Institute of Mental Health and Addiction, Da Costakade 45, 3521 VS Utrecht, The Netherlands;
- Accepted 20 March 2008
- Published Online First 27 May 2008
Objectives: To estimate the prevalence and workplace consequences of adult attention-deficit/hyperactivity disorder (ADHD).
Methods: An ADHD screen was administered to 18–44-year-old respondents in 10 national surveys in the WHO World Mental Health (WMH) Survey Initiative (n = 7075 in paid or self-employment; response rate 45.9–87.7% across countries). Blinded clinical reappraisal interviews were administered in the USA to calibrate the screen. Days out of role were measured using the WHO Disability Assessment Schedule (WHO-DAS). Questions were also asked about ADHD treatment.
Results: An average of 3.5% of workers in the 10 countries were estimated to meet DSM-IV criteria for adult ADHD (inter-quartile range: 1.3–4.9%). ADHD was more common among males than females and less common among professionals than other workers. ADHD was associated with a statistically significant 22.1 annual days of excess lost role performance compared to otherwise similar respondents without ADHD. No difference in the magnitude of this effect was found by occupation, education, age, gender or partner status. This effect was most pronounced in Colombia, Italy, Lebanon and the USA. Although only a small minority of workers with ADHD ever received treatment for this condition, higher proportions were treated for comorbid mental/substance disorders.
Conclusions: ADHD is a relatively common condition among working people in the countries studied and is associated with high work impairment in these countries. This impairment, in conjunction with the low treatment rate and the availability of cost-effective therapies, suggests that ADHD would be a good candidate for targeted workplace screening and treatment programs.
Funding: The surveys discussed in this article were carried out in conjunction with the World Health Organization World Mental Health (WMH) Survey Initiative. These activities were supported by the United States National Institute of Mental Health (R01MH070884), the John D. and Catherine T. MacArthur Foundation, the Pfizer Foundation, the US Public Health Service (R13-MH066849, R01-MH069864, R01 DA016558), the Fogarty International Center (FIRCA R01-TW006481), the Pan American Health Organization, Eli Lilly and Company, Ortho-McNeil Pharmaceutical, Inc., GlaxoSmithKline and Bristol-Myers Squibb Company. The Colombian National Study of Mental Health (NSMH) is supported by the Ministry of Social Protection. The ESEMeD project is funded by the European Commission (contracts QLG5-1999-01042, SANCO 2004123), the Piedmont Region (Italy), Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, Spain (FIS 00/0028), Ministerio de Ciencia y Tecnología, Spain (SAF 2000-158-CE), Departament de Salut, Generalitat de Catalunya, Spain, Instituto de Salud Carlos III (CIBER CB06/02/0046, RETICS RD06/0011 REM-TAP) and other local agencies and by an unrestricted educational grant from GlaxoSmithKline. The Lebanese National Mental Health Survey (LEBANON) is supported by the Lebanese Ministry of Public Health, the WHO (Lebanon), anonymous private donations to IDRAAC, Lebanon, and unrestricted grants from Janssen Cilag, Eli Lilly, GlaxoSmithKline, Roche and Novartis. The Mexican National Comorbidity Survey (MNCS) is supported by The National Institute of Psychiatry Ramon de la Fuente (INPRFMDIES 4280) and by the National Council on Science and Technology (CONACyT-G30544- H), with supplemental support from the Pan American Health Organization (PAHO). The US National Comorbidity Survey Replication (NCS-R) is supported by the National Institute of Mental Health (NIMH; U01-MH60220) with supplemental support from the National Institute of Drug Abuse (NIDA), the Substance Abuse and Mental Health Services Administration (SAMHSA), the Robert Wood Johnson Foundation (RWJF; grant 044708) and the John W. Alden Trust.
Competing interests: Preparation of this report was supported, in part, by an unrestricted educational grant from Eli Lilly and Company in addition to the core WMH funders. Eli Lilly staff were sent an information copy of the paper at the time of submission but were not involved either in designing the study, carrying out analyses, interpreting results, preparing the report, or deciding on whether or not the paper should be published.
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