The short version
- Every number the site uses in an argument is listed here, with its source and whether it has been checked.
- ✓ means the figure was checked against the source itself (journal papers against PubMed).
- SS means a secondary or trade source: named, but open the primary before formal use.
- not yet verified means not yet verified. Those figures are not used as fact until checked.
The usual mix-up
A number with a citation is not automatically a number that has been checked. This register separates the two, so a reader can see which figures are solid and which are still waiting.
The register
| Claim | Number | Source | Status |
|---|---|---|---|
| ADHD heritability (twin) | about 74% | Faraone & Larsson, Mol Psychiatry 2019, DOI 10.1038/s41380-018-0070-0 | ✓ |
| Share of heritability from common variants | about a third | same | ✓ |
| GWAS risk loci | 27 | Demontis et al., Nat Genet 2023, DOI 10.1038/s41588-022-01285-8 | ✓ |
| Combined symptom+diagnosis GWAS | 39 loci, 17 new; 22 potential effector genes | van der Laan et al., Nat Genet 2025, DOI 10.1038/s41588-025-02295-y | ✓ |
| Rare de novo variants | KDM5B high-confidence; about 1,057 genes estimated; 152 trios, 3,206 cases, 5,002 controls | Olfson et al., Nat Commun 2024, DOI 10.1038/s41467-024-50247-7 | ✓ |
| Candidate-gene meta-analysis | DAT1, DRD4, DRD5, 5HTT, HTR1B, SNAP25 significant; heterogeneity for many | Gizer et al., Hum Genet 2009, DOI 10.1007/s00439-009-0694-x | ✓ |
| Platelet VMAT2 | 17% lower Bmax; 11 ADHD vs 14 controls; children/adolescents; authors unsure if primary | Toren et al., Eur Neuropsychopharmacol 2005, DOI 10.1016/j.euroneuro.2004.07.002 | ✓ Tier C |
| VMAT2 deficiency disease | Levodopa associated with worsening; direct dopamine agonists improved | Rilstone et al., N Engl J Med 2013, DOI 10.1056/NEJMoa1207281 | ✓ |
| DRD systematic review | 734 patients, 151 asymptomatic GCH1 carriers; red flags | Weissbach et al., Mov Disord 2022, DOI 10.1002/mds.28874 | ✓ |
| Autism heritability | median 80.8% (73.2 to 85.5%); 2,001,631 individuals; 22,156 with ASD | Bai et al., JAMA Psychiatry 2019, DOI 10.1001/jamapsychiatry.2019.1411 | ✓ |
| Autism mortality (Sweden) | 2.60% vs 0.91%; OR 2.56 (2.38 to 2.76); 27,122 vs 2,672,185 | Hirvikoski et al., Br J Psychiatry 2016, DOI 10.1192/bjp.bp.114.160192 | ✓ |
| Life expectancy, diagnosed ADHD (UK) | apparent reduction 6.78 years (CI 4.50 to 9.11) males; 8.64 (6.55 to 10.91) females; 30,039 vs 300,390; data 2000 to 2019 | O'Nions et al., Br J Psychiatry 2025, DOI 10.1192/bjp.2024.199 | ✓ Use "apparent"; authors note limits and non-generalisability |
| Methylphenidate price trend | fell for ten years to about £2.37; first concession December 2022 at £4.88; 13 further concessions | WaveData (trade source) | SS, fetched; verify current |
| Adult ADHD drug efficacy | amphetamines SMD −0.79 (−0.99 to −0.58); methylphenidate −0.49; atomoxetine −0.45; side-effect dropout OR 3.26 (1.54 to 6.92) for amphetamines; insufficient data at 26 and 52 weeks | Cortese et al., Lancet Psychiatry 2018, DOI 10.1016/S2215-0366(18)30269-4 | ✓ Quote the benefit and the dropout and evidence-horizon caveats together |
| Suicide-related events, within-patient | HR 0.89 (0.79 to 1.00) overall; 0.81 (0.70 to 0.94) stimulants; population-level HR 1.31 (1.19 to 1.44); 37,936 patients | Chen et al., BMJ 2014;348:g3769, DOI 10.1136/bmj.g3769, PMID 24942388 | ✓ Observational; say "associated with" |
| Road-crash emergency visits, within-individual | men OR 0.62 (0.56 to 0.67); women OR 0.58 (0.53 to 0.62); up to 22.1% avoidable (modelled); 2,319,450 patients | Chang et al., JAMA Psychiatry 2017;74(6):597-603, DOI 10.1001/jamapsychiatry.2017.0659, PMID 28492937 | ✓ Observational claims data |
| GMC continuity of care | "Continuity of care is important for all patients, but especially those who may struggle to navigate their healthcare journey or advocate for themselves." (para 65). Para 59 is the leaders' duty to act on paras 56 and 57 and is NOT the continuity paragraph | GMC Good Medical Practice 2024, Domain 3 | ✓ fetched; copy from the GMC page before filing; sub-points 65.1 to 65.4 wording not yet verified |
| ICD-11 codes | ADHD 6A05; ASD 6A02; FND (dissociative neurological symptom disorder) 6B60; HSP 8B44. 8E20 is persistent vegetative state and 8A40.Z is multiple sclerosis, unspecified | WHO ICD-11 MMS (checked on a mirror) | not yet verified |
| Waiting numbers | "up to 549,000 waiting, March 2025" | NHS England Digital | not yet verified |
| ADHD cost | £17bn | Daley et al. 2019 extrapolation | Show as scale only |
How to read the numbers
- Population, not person. Heritability, mortality and life-expectancy figures describe groups. They do not predict any one person's outcome.
- Observational, not causal. The suicide-related and road-crash figures come from observational within-person designs. They show an association with medication periods, not proof of cause.
- Benefit with its caveats. The adult medication figures are quoted together with the side-effect dropout figure and the lack of data beyond 26 and 52 weeks.
- Scale, not measurement. The £17bn figure is an extrapolation from Danish data. It shows the likely scale, not a measured UK cost.
Limits
This register is only as current as its last update. Figures marked not yet verified or SS must be checked against the primary source before anyone relies on them. Nothing here is medical advice.
Sources
Each row names its source. DOIs link through from the articles that use them; see the evidence map and how evidence is handled.