Most autistic adults in England have no diagnosis
Between 59 and 72% of autistic people in England are estimated to be undiagnosed. Recorded diagnosis runs from 2.94% among 10- to 14-year-olds down to about 1 in 6,000 among people aged 70 and over.
We have not finished checking this source. No judgement either way. how we score evidence
Caveat on this rating: Scope and construct, both mandatory here. The 59-72% range is an exploratory projection, not a measurement: recorded diagnoses in English primary-care data were compared against community prevalence estimates derived from separate instrument-based studies, so the range inherits the uncertainty of both inputs. It is England; no equivalent US series exists, and the citable US statement on adult assessment access is qualitative rather than statistical. What the age gradient documents is a change in who gets identified, not a change in who is autistic, and nothing here is a claim about any individual's diagnosis or support needs. The waiting-time figures behind the queue sentence are NHS England's "Autism Waiting Time Statistics" for June 2026 - 294,792 open referrals, 86.8% open at least 13 weeks - published as official statistics in development, whose own caveats note that community-paediatric activity is not yet separately identifiable.
Between 59 and 72% of autistic people in England are estimated to be undiagnosed.
Significant findings
O'Nions and colleagues compared autism diagnoses recorded in English primary-care data against community estimates of how many autistic people there are. The recorded count is a fraction of the expected one.
The age gradient shows why. Among 10- to 14-year-olds, 2.94% had a recorded diagnosis. Among people aged 70 and over, 0.02% did - about 1 in 6,000. Autism was treated as a childhood condition for most of the time it has existed as a diagnosis, so people who were children before it was widely recognised were largely never assessed.
Getting assessed as an adult now is mostly a matter of queueing. In England, the large majority of people with an open autism referral have already waited longer than the recommended 13 weeks.
Worth asking
This is why adults wonder about themselves without a diagnosis, and it is a structural reason rather than a personal one. If you are wondering: ask what an evaluation would involve in your case, what the wait is where you live, and what support is available that does not require a diagnosis at all.
Source
Autism in England: assessing underdiagnosis in a population-based cohort study of prospectively collected primary care data — O'Nions E, Petersen I, Buckman JEJ, et al. (2023)
Read the source: https://doi.org/10.1016/j.lanepe.2023.100626
DOI: 10.1016/j.lanepe.2023.100626
How this was scored
- Study design
- not recorded
- Funding
- not recorded
- Published in
- not recorded
- Sample size
- not recorded
- Preregistered
- not recorded
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
We have not finished checking this source, so there is no scoring to show yet. “We have not checked this yet” and “this is disputed” are different statements, so no scored band is shown rather than a low one.
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Published August 31, 2026.
Questions
How strong is the evidence behind this?
Resolv rates this source "not yet assessed". We have not finished checking this source. No judgement either way. One caveat travels with that badge: Scope and construct, both mandatory here. The 59-72% range is an exploratory projection, not a measurement: recorded diagnoses in English primary-care data were compared against community prevalence estimates derived from separate instrument-based studies, so the range inherits the uncertainty of both inputs. It is England; no equivalent US series exists, and the citable US statement on adult assessment access is qualitative rather than statistical. What the age gradient documents is a change in who gets identified, not a change in who is autistic, and nothing here is a claim about any individual's diagnosis or support needs. The waiting-time figures behind the queue sentence are NHS England's "Autism Waiting Time Statistics" for June 2026 - 294,792 open referrals, 86.8% open at least 13 weeks - published as official statistics in development, whose own caveats note that community-paediatric activity is not yet separately identifiable. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Autism in England: assessing underdiagnosis in a population-based cohort study of prospectively collected primary care data — O'Nions E, Petersen I, Buckman JEJ, et al. (2023). DOI: 10.1016/j.lanepe.2023.100626. The full source is linked on this page so you can read it yourself.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.