Registration gives the benefit of site update e-mails and additional information from Takeda on new education materials and events.
ADHD Institute Register

What is ADHD?

Attention-deficit hyperactivity disorder (ADHD), or hyperkinetic disorder (HKD), is a diverse neurodevelopmental condition characterised by symptoms of inattention, hyperactivity and impulsivity, and can have a significant impact on affected individuals’ lives.1,2 There are two key medical classification systems used to define ADHD:

  • The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders – 5th Edition (DSM-5TM) medical classification system which defines ADHD as “a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development”.1
  • The International Classification of Diseases 11th Revision (ICD-11), which defines ADHD as “a persistent pattern of inattention and/or hyperactivity-impulsivity that has a direct negative impact on academic, occupational or social functioning”.2

How common is ADHD?

ADHD is known to persist across the lifespan and affects people of all ages. ADHD prevalence rates vary between children, adolescents and adults (Figure 1), and by gender and symptom presentation.1,3-8

Figure 1: Summary of ADHD prevalence rates in different age groups. Figure developed from multiple sources.3-6,9

Summary of ADHD prevalence rates in different age groups

What comorbid psychiatric disorders are associated with ADHD?

The majority of adults with ADHD have a diagnosed or undiagnosed psychiatric comorbidity, which can complicate diagnosis and treatment of ADHD (Figure 2).10-12

Figure 2: Main comorbid psychiatric disorders in adult ADHD. Reproduced with permission from Kooij JJS et al. J Atten Disord 2012; 16(5 Suppl): 3S-19S.13

Main comorbid psychiatric disorders in adult ADHD

What causes ADHD?

The aetiology of ADHD is complex and is thought to have a neurobiological component, an underlying genetic component and be associated with several environmental risk factors, which may increase the likelihood of some ADHD symptoms.14-53

What is the impact of ADHD?

ADHD can have a significant social impact on affected individual’s lives, causing disruption at school, work and in relationships.54-61 Symptoms of ADHD may also increase risk-taking behaviour.54,62,63 Consequently, the quality of life of individuals with ADHD may be impaired, although some positive aspects of ADHD have been reported.55,56,64-67 ADHD can also be associated with substantial economic burden for the individual, their family and societal healthcare services.68,69

  1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. 2013.
  2. World Health Organization. ICD-11: International Classification of Diseases 11th Revision. 2018. Available at: Accessed January 2021.
  3. Wichstrøm L, Berg-Nielsen TS, Angold A, et al. Prevalence of psychiatric disorders in preschoolers. J Child Psychol Psychiatry 2012; 53: 695-705.
  4. Schlack R, Hölling H, Kurth BM, et al. The prevalence of attention-deficit/hyperactivity disorder (ADHD) among children and adolescents in Germany. Initial results from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2007; 50: 827-835.
  5. Canals J, Morales-Hidakgo P, Jane M, et al. Prevalence in Spanish preschoolers: comorbidity, socio-demographic factors, and functional consequences. J Atten Disord 2016; 22: 143-153.
  6. Fayyad J, Sampson NA, Hwang I, et al. The descriptive epidemiology of DSM-IV Adult ADHD in the World Health Organization World Mental Health Surveys. Atten Defic Hyperact Disord 2017; 9: 47-65.
  7. Nøvik TS, Hervas A, Ralston SJ, et al. Influence of gender on attention-deficit/hyperactivity disorder in Europe–ADORE. Eur Child Adolesc Psychiatry 2006; 15(Suppl 1): I15-I24.
  8. Willcutt EG. The prevalence of DSM-IV attention-deficit/hyperactivity disorder: a meta-analytic review. Neurotherapeutics 2012; 9: 490-499.
  9. Dobrosavljevic M, Solares C, Cortese S, et al. Prevalence of attention-deficit/hyperactivity disorder in older adults: A systematic review and meta-analysis. Neurosci Biobehav Rev 2020; 118: 282-289.
  10. NICE guideline 2018. Attention deficit hyperactivity disorder: diagnosis and management. Available at: Accessed January 2021.
  11. Canadian ADHD Resource Alliance (CADDRA). Canadian ADHD Practice Guidelines. Edition 4.1. Toronto, ON: CADDRA, 2020.
  12. Kooij JJS, Bijlenga D, Salerno L, et al. Updated European Consensus Statement on diagnosis and treatment of adult ADHD. Eur Psychiatry 2019; 56: 14-34.
  13. Kooij JJ, Huss M, Asherson P, et al. Distinguishing comorbidity and successful management of adult ADHD. J Atten Disord 2012; 16(5 Suppl): 3S-19S.
  14. Proal E, Reiss PT, Klein RG, et al. Brain gray matter deficits at 33-year follow-up in adults with attention-deficit/hyperactivity disorder established in childhood. Arch Gen Psychiatry 2011; 68: 1122-1134.
  15. Nakao T, Radua J, Rubia K, et al. Gray matter volume abnormalities in ADHD: voxel-based meta-analysis exploring the effects of age and stimulant medication. Am J Psychiatry 2011; 168: 1154-1163.
  16. Ellison-Wright I, Ellison-Wright Z, Bullmore E. Structural brain change in attention deficit hyperactivity disorder identified by meta-analysis. BMC Psychiatry 2008; 8: 51.
  17. Davenport ND, Karatekin C, White T, et al. Differential fractional anisotropy abnormalities in adolescents with ADHD or schizophrenia. Psychiatry Res 2010; 181: 193-198.
  18. Shaw P, Sudre G, Wharton A, et al. White matter microstructure and the variable adult outcome of childhood attention deficit hyperactivity disorder. Neuropsychopharmacology 2015; 40: 746-754.
  19. Valera EM, Faraone SV, Murray KE, et al. Meta-analysis of structural imaging findings in attention-deficit/hyperactivity disorder. Biol Psychiatry 2007; 61: 1361-1369.
  20. Ivanov I, Bansal R, Hao X, et al. Morphological abnormalities of the thalamus in youths with attention deficit hyperactivity disorder. Am J Psychiatry 2010; 167: 397-408.
  21. Hoogman M, Rijpkema M, Janss L, et al. Current self-reported symptoms of attention deficit/hyperactivity disorder are associated with total brain volume in healthy adults. PLoS One 2012; 7: e31273.
  22. Shaw P, Lerch J, Greenstein D, et al. Longitudinal mapping of cortical thickness and clinical outcome in children and adolescents with attention-deficit/hyperactivity disorder. Arch Gen Psychiatry 2006; 63: 540-549.
  23. Shaw P, Eckstrand K, Sharp W, et al. Attention-deficit/hyperactivity disorder is characterized by a delay in cortical maturation. Proc Natl Acad Sci U S A 2007; 104: 19649-19654.
  24. Shaw P, Malek M, Watson B, et al. Development of cortical surface area and gyrification in attention-deficit/hyperactivity disorder. Biol Psychiatry 2012; 72: 191-197.
  25. Makris N, Biederman J, Valera EM, et al. Cortical thinning of the attention and executive function networks in adults with attention-deficit/hyperactivity disorder. Cereb Cortex 2007; 17: 1364-1375.
  26. Purper-Ouakil D, Ramoz N, Lepagnol-Bestel AM, et al. Neurobiology of attention deficit/hyperactivity disorder. Pediatr Res 2011; 69(5 Pt 2): 69R-76R.
  27. Cortese S, Kelly C, Chabernaud C, et al. Toward systems neuroscience of ADHD: a meta-analysis of 55 fMRI studies. Am J Psychiatry 2012; 169: 1038-1055.
  28. Morein-Zamir S, Dodds C, van Hartevelt TJ, et al. Hypoactivation in right inferior frontal cortex is specifically associated with motor response inhibition in adult ADHD. Hum Brain Mapp 2014; 35: 5141-5152.
  29. Karch S, Voelker JM, Thalmeier T, et al. Deficits during voluntary selection in adult patients with ADHD: new insights from single-trial coupling of simultaneous EEG/fMRI. Front Psychiatry 2014; 5: 41.
  30. Dickstein SG, Bannon K, Castellanos FX, et al. The neural correlates of attention deficit hyperactivity disorder: an ALE meta-analysis. J Child Psychol Psychiatry 2006; 47: 1051-1062.
  31. Cubillo A, Halari R, Giampietro V, et al. Fronto-striatal underactivation during interference inhibition and attention allocation in grown up children with attention deficit/hyperactivity disorder and persistent symptoms. Psychiatry Res 2011; 193: 17-27.
  32. Peterson BS, Potenza MN, Wang Z, et al. An FMRI study of the effects of psychostimulants on default-mode processing during Stroop task performance in youths with ADHD. Am J Psychiatry 2009; 166: 1286-1294.
  33. Liddle EB, Hollis C, Batty MJ, et al. Task-related default mode network modulation and inhibitory control in ADHD: effects of motivation and methylphenidate. J Child Psychol Psychiatry 2011; 52: 761-771.
  34. Economidou D, Theobald DE, Robbins TW, et al. Norepinephrine and dopamine modulate impulsivity on the five-choice serial reaction time task through opponent actions in the shell and core sub-regions of the nucleus accumbens. Neuropsychopharmacology 2012; 37: 2057-2066.
  35. Volkow ND, Wang GJ, Newcorn J, et al. Depressed dopamine activity in caudate and preliminary evidence of limbic involvement in adults with attention-deficit/hyperactivity disorder. Arch Gen Psychiatry 2007; 64: 932-940.
  36. Liu YP, Lin YL, Chuang CH, et al. Alpha adrenergic modulation on effects of norepinephrine transporter inhibitor reboxetine in five-choice serial reaction time task. J Biomed Sci 2009; 16: 72.
  37. Del Campo N, Chamberlain SR, Sahakian BJ, et al. The roles of dopamine and noradrenaline in the pathophysiology and treatment of attention-deficit/hyperactivity disorder. Biol Psychiatry 2011; 69: e145-157.
  38. Seeger G, Schloss P, Schmidt MH. Functional polymorphism within the promotor of the serotonin transporter gene is associated with severe hyperkinetic disorders. Mol Psychiatry 2001; 6: 235-238.
  39. Maltezos S, Horder J, Coghlan S, et al. Glutamate/glutamine and neuronal integrity in adults with ADHD: a proton MRS study. Transl Psychiatry 2014; 4: e373.
  40. Perlov E, Philipsen A, Hesslinger B, et al. Reduced cingulate glutamate/glutamine-to-creatine ratios in adult patients with attention deficit/hyperactivity disorder — a magnet resonance spectroscopy study. J Psychiatr Res 2007; 41: 934-941.
  41. Larsson H, Chang Z, D’Onofrio BM, et al. The heritability of clinically diagnosed attention deficit hyperactivity disorder across the lifespan. Psychol Med 2014; 44: 2223-2229.
  42. Larsson H, Asherson P, Chang Z, et al. Genetic and environmental influences on adult attention deficit hyperactivity disorder symptoms: a large Swedish population-based study of twins. Psychol Med 2013; 43: 197-207.
  43. Galéra C, Côté SM, Bouvard MP, et al. Early risk factors for hyperactivity-impulsivity and inattention trajectories from age 17 months to 8 years. Arch Gen Psychiatry 2011; 68: 1267-1275.
  44. Langley K, Holmans PA, van den Bree MB, et al. Effects of low birth weight, maternal smoking in pregnancy and social class on the phenotypic manifestation of attention deficit hyperactivity disorder and associated antisocial behaviour: investigation in a clinical sample. BMC Psychiatry 2007; 7: 26.
  45. Froehlich TE, Lanphear BP, Auinger P, et al. Association of tobacco and lead exposures with attention-deficit/hyperactivity disorder. Pediatrics 2009; 124: e1054-e1063.
  46. Hjern A, Weitoft GR, Lindblad F. Social adversity predicts ADHD-medication in school children–a national cohort study. Acta Paediatr 2010; 99: 920-924.
  47. Rowland AS, Skipper BJ, Rabiner DL, et al. Attention-deficit/hyperactivity disorder (ADHD): interaction between socioeconomic status and parental history of ADHD determines prevalence. J Child Psychol Psychiatry 2018; 59: 213-222.
  48. Brookes KJ, Mill J, Guindalini C, et al. A common haplotype of the dopamine transporter gene associated with attention-deficit/hyperactivity disorder and interacting with maternal use of alcohol during pregnancy. Arch Gen Psychiatry 2006; 63: 74-81.
  49. Grizenko N, Fortier ME, Zadorozny C, et al. Maternal stress during pregnancy, ADHD symptomatology in children and genotype: gene-environment interaction. J Can Acad Child Adolesc Psychiatry 2012; 21: 9-15.
  50. Kahn RS, Khoury J, Nichols WC, et al. Role of dopamine transporter genotype and maternal prenatal smoking in childhood hyperactive-impulsive, inattentive, and oppositional behaviors. J Pediatr 2003; 143: 104-110.
  51. Neuman RJ, Lobos E, Reich W, et al. Prenatal smoking exposure and dopaminergic genotypes interact to cause a severe ADHD subtype. Biol Psychiatry 2007; 61: 1320-1328.
  52. Sánchez-Mora C, Richarte V, Garcia-Martínez I, et al. Dopamine receptor DRD4 gene and stressful life events in persistent attention deficit hyperactivity disorder. Am J Med Genet B Neuropsychiatr Genet 2015; 168: 480-491.
  53. Jacob CP, Nguyen TT, Dempfle A, et al. A gene-environment investigation on personality traits in two independent clinical sets of adult patients with personality disorder and attention deficit/hyperactive disorder. Eur Arch Psychiatry Clin Neurosci 2010; 260: 317-326.
  54. Biederman J, Faraone SV, Spencer TJ, et al. Functional impairments in adults with self-reports of diagnosed ADHD: a controlled study of 1001 adults in the community. J Clin Psychiatry 2006; 67: 524-540.
  55. Caci H, Doepfner M, Asherson P, et al. Daily life impairments associated with self-reported childhood/adolescent attention-deficit/hyperactivity disorder and experiences of diagnosis and treatment: results from the European Lifetime Impairment Survey. Eur Psychiatry 2014; 29: 316-323.
  56. Brod M, Pohlman B, Lasser R, et al. Comparison of the burden of illness for adults with ADHD across seven countries: a qualitative study. Health Qual Life Outcomes 2012; 10: 47.
  57. De Graaf R, Kessler RC, Fayyad J, et al. 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. Occup Environ Med 2008; 65: 835-842.
  58. Shifrin JG, Proctor BE, Prevatt FF. Work performance differences between college students with and without ADHD. J Atten Disord 2010; 13: 489-496.
  59. Halmøy A, Fasmer OB, Gillberg C, et al. Occupational outcome in adult ADHD: impact of symptom profile, comorbid psychiatric problems, and treatment: a cross-sectional study of 414 clinically diagnosed adult ADHD patients. J Atten Disord 2009; 13: 175-187.
  60. Cussen A, Sciberras E, Ukoumunne OC, et al. Relationship between symptoms of attention-deficit/hyperactivity disorder and family functioning: a community-based study. Eur J Pediatr 2012; 171: 271-280.
  61. Pitts M, Mangle L, Asherson P. Impairments, diagnosis and treatments associated with attention-deficit/hyperactivity disorder (ADHD) in UK adults: results from the lifetime impairment survey. Arch Psychiatr Nurs 2015; 29: 56-63.
  62. Humphreys KL, Lee SS. Risk taking and sensitivity to punishment in children with ADHD, ODD, ADHD+ODD, and controls. J Psychopathol Behav Assess 2011; 33: 299-307.
  63. Sørensen L, Sonuga-Barke E, Eichele H, et al. Suboptimal decision making by children with ADHD in the face of risk: poor risk adjustment and delay aversion rather than general proneness to taking risks. Neuropsychology 2017; 31: 119-128.
  64. Caci H, Asherson P, Donfrancesco R, et al. Daily life impairments associated with childhood/adolescent attention-deficit/hyperactivity disorder as recalled by adults: results from the European Lifetime Impairment Survey. CNS Spectr 2015; 20: 112-121.
  65. Grenwald-Mayes G. Relationship between current quality of life and family of origin dynamics for college students with attention-deficit/hyperactivity disorder. J Atten Disord 2002; 5: 211-222.
  66. O’Callaghan P, Sharma D. Severity of symptoms and quality of life in medical students with ADHD. J Atten Disord 2014; 18: 654-658.
  67. Hoogman M, Stolte M, Baas M, et al. Creativity and ADHD: A review of behavioral studies, the effect of psychostimulants and neural underpinnings. Neurosci Biobehav Rev 2020; 119: 66-85.
  68. Telford C, Green C, Logan S, et al. Estimating the costs of ongoing care for adolescents with attention-deficit hyperactivity disorder. Soc Psychiatry Psychiatr Epidemiol 2013; 48: 337-344.
  69. Le HH, Hodgkins P, Postma MJ, et al. Economic impact of childhood/adolescent ADHD in a European setting: the Netherlands as a reference case. Eur Child Adolesc Psychiatry 2014; 23: 587-598.
Filter content by:

ADHD Institue logo

You’re now being transferred to

and are leaving the ADHD Institute site

Takeda has no influence or control over the content of this third party website.

Continue Cancel