Whilst attention-deficit hyperactivity disorder (ADHD) was once considered to be a childhood disease with a decline in symptoms during maturation to adulthood1 it is now acknowledged to persist into adulthood in an estimated 50–66% of individuals.2-5 The prevalence of ADHD in very young children (aged <6 years) or later in adult life (aged >44 years), is less well-studied.6

Pre-school children

Prevalence estimates of ADHD in pre-school children (aged <6 years) are limited.

  • A European study in which 1676 parents (mean age of children: 5.7 years) completed school-entry questionnaires that included all items of the Diagnostic and Statistical Manual of Mental Disorders – 4th edition (DSM-IV)§ for ADHD, indicated that 6.4% of the pre-school children had ADHD7
  • The parents of 7569 boys and 7267 girls (aged 3–17 years) enrolled in the German Health Interview and Examination Survey for Children & Adolescents (KiGGS) answered self-administered questionnaires that included the Strengths and Difficulties Questionnaire (SDQ). Results from the survey indicated that 1.8% of pre-school children (aged 3–6 years) had ADHD.8
  • In a Norwegien study, children born in 2003/2004 who visited regular community check-ups for 4-year-olds, whose parents consented to take part in the study (n=2475) were screened for behavioural and emotional problems with the SDQ. Results estimated that 1.9% of patients had ADHD.9

School-age children and adolescents

ADHD is most commonly diagnosed in school-aged children.10 Results from meta-regression analyses have estimated a worldwide prevalence of ADHD in people aged ≤18 years of between 5.29%11§ and 7.1%. A recent study (2014) which updated these analyses concluded that there was no evidence to suggest an increase in the prevalence of ADHD in children and adolescents over the past three decades.12§


Predictors for persistence of ADHD2-5 into adulthood may include severity of symptoms,5 psychosocial adversity and psychiatric comorbidities.13

The worldwide ADHD prevalence in adults (aged 18–44 years) was estimated at 3.4% overall (range 1.2–7.3%) by the World Health Organization across 10 countries in Europe, the Americas, Columbia, Mexico and the Middle East.14§ In addition, results from a worldwide meta-regression analysis of 11 studies of adult ADHD (n=14,081 participants) estimated the prevalence to be 5.0% in people aged ≥19 years, although this was deemed representative of ‘younger adults’ as the majority of studies focused on adults aged <25 years.

Worldwide prevalence of ADHD across different age groups: a summary

Age group Prevalence (%)
Pre-school children (Europe) 1.8–6.47-9
Children and adolescents
3.4 overall (range 1.2–7.3%)13

§These studies were conducted prior to publication of the Diagnostic and Statistical Manual of Mental Disorders – 5th Edition (DSM-5TM).


View references

  1. Biederman J, Mick E, Faraone SV. Age-dependent decline of symptoms of attention deficit hyperactivity disorder: impact of remission definition and symptom type. Am J Psychiatry 2000; 157: 816-818.
  2. Barkley RA, Fischer M, Smallish L, et al. The persistence of attention-deficit/hyperactivity disorder into young adulthood as a function of reporting source and definition of disorder. J Abnorm Psychol 2002; 111: 279-289.
  3. Ebejer JL, Medland SE, van der Werf J, et al. Attention deficit hyperactivity disorder in Australian adults: prevalence, persistence, conduct problems and disadvantage. PLoS One 2012; 7: e47404.
  4. Faraone SV, Biederman J, Mick E. The age-dependent decline of attention deficit hyperactivity disorder: a meta-analysis of follow-up studies. Psychol Med 2006; 36: 159-165.
  5. Lara C, Fayyad J, de Graaf R, et al. Childhood predictors of adult attention-deficit/hyperactivity disorder: results from the World Health Organization World Mental Health Survey Initiative. Biol Psychiatry 2009; 65: 46-54.
  6. Willcutt EG. The prevalence of DSM-IV attention-deficit/hyperactivity disorder: a meta-analytic review. Neurotherapeutics 2012; 9: 490-499.
  7. Niemczyk J, Equit M, Braun-Bither K, et al. Prevalence of incontinence, attention deficit/hyperactivity disorder and oppositional defiant disorder in preschool children. Eur Child Adolesc Psychiatry 2014 [Epub ahead of print].
  8. Schlack R, Holling 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 Survery for Children and Adolescents (KiGGS). Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2007; 50: 827-835.
  9. Wichstrøm L, Berg-Nielsen TS, Angold A, et al. Prevalence of psychiatric disorders in preschoolers, J Child Psychol Psychiatry 2012; 53: 695-7-5.
  10. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. 2013.
  11. Polanczyk G, de Lima MS, Horta BL, et al. The worldwide prevalence of ADHD: a systematic review and metaregression analysis. Am J Psychiatry 2007; 164: 942-948.
  12. Polanczyk GV, Willcutt EG, Salum GA, et al. ADHD prevalence estimates across three decades: an updated systematic review and meta-regression analysis. Int J Epidemiol 2014; 43: 434-442.
  13. Biederman J, Petty CR, O'Connor KB, et al. Predictors of persistence in girls with attention deficit hyperactivity disorder: results from an 11-year controlled follow-up study. Acta Psychiatr Scand 2012; 125: 147-156.
  14. Fayyad J, de Graaf R, Kessler R, et al. Cross-national prevalence and correlates of adult attention-deficit hyperactivity disorder. Br J Psychiatry 2007; 190: 402-409.

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Childhood/Adolescent ADHD and the brain animation by Dr Mitul Mehta

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ADHD can continue to affect patients’ functioning and quality of life beyond childhood into adolescence and adulthood

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