Sources

Everything on this site that makes a claim about ADHD links to where that claim comes from. These are the sources we used.

• Attention deficit hyperactivity disorder: diagnosis and management (NG87)
  National Institute for Health and Care Excellence (NICE), UK
  www.nice.org.uk/guidance/ng87
  Clinical guideline. Published 2018, recommendations amended through 2024. Link checked 2026-11-01.
• About Attention-Deficit / Hyperactivity Disorder (ADHD)
  Centers for Disease Control and Prevention (CDC), USA
  www.cdc.gov/adhd/about/index.html
  Page reviewed 21 October 2026. Link checked 2026-11-01.
• Attention-Deficit/Hyperactivity Disorder (ADHD)
  National Institute of Mental Health (NIMH), USA
  www.nimh.nih.gov/health/topics/attention-deficit-hyperactivity-disorder-adhd
  Page last reviewed August 2026. Link checked 2026-11-01.
• The World Federation of ADHD International Consensus Statement: 208 evidence-based conclusions about the disorder
  Faraone SV et al., Neuroscience & Biobehavioral Reviews, 2021;128:789–818
  doi.org/10.1016/j.neubiorev.2021.01.022 PubMed
  Consensus review restricted to meta-analyses and very large studies. Reports ADHD in about 5.9% of youth and 2.5% of adults. Retrieved via PubMed (PMID 33549739). Link checked 2026-11-01.
• The prevalence of adult attention-deficit hyperactivity disorder: a global systematic review and meta-analysis
  Song P et al., Journal of Global Health, 2021;11:04009
  doi.org/10.7189/jogh.11.04009 PubMed
  Estimates persistent adult ADHD at 2.58% and symptomatic adult ADHD at 6.76%, adjusted to the 2020 global population. Retrieved via PubMed (PMID 33692893). Link checked 2026-11-01.
• Meta-analysis: altered perceptual timing abilities in attention-deficit/hyperactivity disorder
  Marx I, Cortese S, Koelch MG, Hacker T., Journal of the American Academy of Child & Adolescent Psychiatry, 2022;61(7):866–880
  doi.org/10.1016/j.jaac.2021.12.004 PubMed
  55 studies. Finds a broad range of timing differences, including more variable estimation of durations lasting several seconds. Retrieved via PubMed (PMID 34923055). Link checked 2026-11-01.
• Time perception deficits in children and adolescents with ADHD: a meta-analysis
  Zheng Q, Wang X, Chiu KY, Shum KK., Journal of Attention Disorders, 2022;26(2):267–281
  doi.org/10.1177/1087054720978557 PubMed
  27 studies, 1,620 participants with ADHD. Found less accurate and less precise time perception, and a greater tendency to overestimate time. Retrieved via PubMed (PMID 33302769). Link checked 2026-11-01.
• Does forming implementation intentions help people with mental health problems to achieve goals? A meta-analysis of experimental studies
  Toli A, Webb TL, Hardy GE., British Journal of Clinical Psychology, 2016;55(1):69–90
  doi.org/10.1111/bjc.12086 PubMed
  29 experimental studies. "If-then" plans that tie an action to a specific cue had a large effect on goal attainment. Not an ADHD-specific study. Retrieved via PubMed (PMID 25965276). Link checked 2026-11-01.
• ADHD among rural southeastern Nigerian primary school children: prevalence and psychosocial factors
  Ndukuba AC, Odinka PC, Muomah RC, Obindo JT, Omigbodun OO., Journal of Attention Disorders, 2017;21(10):865–871
  doi.org/10.1177/1087054714543367 PubMed
  181 pupils in one rural community in south-eastern Nigeria; 6.6% met criteria on the screening instruments used. A single small local study, not a national figure. The authors note that care is concentrated in cities. Retrieved via PubMed (PMID 25069585). Link checked 2026-11-01.
• ICD-11 for Mortality and Morbidity Statistics — 6A05 Attention deficit hyperactivity disorder
  World Health Organization
  icd.who.int/browse/2025-01/mms/en
  ADHD is classified under neurodevelopmental disorders (code 6A05). Search the browser for 6A05. Link checked 2026-11-01.