Growing Older Autistic: More Health Needs, Few Diagnoses, Little Research

Autistic people grow old like everyone else, but almost everything known about autism comes from studying children. The evidence that does exist on autistic older adults points one way: more long-term health conditions, more diagnoses of Parkinson's disease and dementia, mental health needs that persist into later life, and a generation that was mostly never diagnosed at all.

Today's older autistic people grew up when autism was barely known. As one English research team puts it, "autism has long been viewed as a paediatric condition, meaning that many autistic adults missed out on a diagnosis as children when autism was little known"^[1]. So later life often arrives without a name for a lifetime of difference. It is the retired person who has spent decades working out, alone, why noisy rooms and small talk cost so much. It is the older adult with an intellectual disability whose pain is noticed late, because nobody learned how they communicate it. And the GP surgeries, memory clinics and care homes they rely on were rarely designed with autistic people in mind.

Most older autistic people have never been diagnosed

In England, researchers analysed GP records for 602,433 people registered in 2018. Recorded diagnoses fell steeply with age: 2.94% of 10- to 14-year-olds had an autism diagnosis, against 0.02% of people aged 70 and over. New diagnoses followed the same slope. In 2018 about 1 in 250 children aged 5 to 9 received one, compared with about 1 in 4,000 adults aged 20 to 49 and about 1 in 18,000 people aged 50 and over^[1].

Comparing these figures with community prevalence estimates, the team projected that, as of 2018, around 463,500 people in England had been diagnosed autistic. Between 435,700 and 1,197,300 more may be autistic and undiagnosed, which is 59–72% of all autistic people. The projections are exploratory, but the authors' conclusion is direct: the age differences "suggest an urgent need to improve access to adult autism diagnostic services"^[1]. Citing this study and a 2025 review of ageing research, the authors of a 2026 UK paper described "approximately nine out of ten autistic people aged over 50 in the UK being potentially undiagnosed, or misdiagnosed with another condition"^[3]. Our article on diagnosis in adulthood looks at what a late diagnosis changes.

The older autistic people in health records are a minority, often those with the most visible support needs. In a national US study of autistic adults aged 65 and over, more than 43% of the autistic group had an intellectual disability, against 0.2% of the comparison group^[4]. The findings below describe people who were diagnosed, and may not look the same for the many never recognised.

Long-term conditions are more common, and some far more so

That US study used Medicare claims from 2016–17. It compared 4,685 autistic adults aged 65 and over with 46,850 Medicare beneficiaries matched on age and sex, and found "significantly greater odds of nearly all physical health conditions"^[4]. Some of the widest gaps:

• Epilepsy: 26.4% of autistic older adults vs 1.9% of the comparison group (adjusted odds ratio 18.9).
• Parkinson's disease: 6.6% vs 1.2% (adjusted odds ratio 6.1).
• Cognitive disorders, a category including dementia and delirium: 25.2% vs 4.9% (adjusted odds ratio 8.4).

"Other" gut conditions such as gastroenteritis and constipation were recorded for 51.2% vs 17.6%, and osteoporosis for 16.6% vs 4.9%. Common conditions of later life were also more frequent: heart disease 54.2% vs 37.1%, high blood pressure 66.5% vs 51.2%, and diabetes 36.6% vs 27.4%^[4].

Three cautions apply. The odds ratios were adjusted for sex, age, race/ethnicity, rural residence and income, but not for intellectual disability, which was far more common in the autistic group^[4]. For conditions as common as heart disease, odds ratios exaggerate the difference in risk, so the percentages are the fairer comparison. And these are claims records for a generation "all born before the year 1950"; the authors say the findings "may or may not be predictive of the outcomes of future generations of autistic older adults"^[4]. Even so, the pattern is consistent. In an earlier study of 1,507 autistic adults of all ages at Kaiser Permanente Northern California (2008–12), "nearly all medical conditions" were more common than in 15,070 matched controls, including "rarer conditions, such as stroke and Parkinson's disease"^[5]. How these conditions shape the mortality gap is covered in our article on autism, mortality and life expectancy.

Parkinson's: a signal that keeps appearing

A small study in Western Australia in 2015 examined autistic adults over 39 for parkinsonism, the movement symptoms seen in Parkinson's. Among the 20 participants not taking atypical antipsychotics, 4 (20%) met the criteria, which the authors called "a high frequency"^[6]. The Medicare data, above, showed the same signal^[4].

The largest study comes from Sweden. It followed 2,278,565 people born between 1974 and 1999 from age 20 to the end of 2022, so it covers Parkinson's arising well before old age. Parkinson's was diagnosed in 24 of 51,954 autistic people (0.05%) and 438 of 2,226,611 non-autistic people (0.02%). That is 4.43 times the incidence rate. The estimate held after adjusting for sex, socioeconomic status and family history. Antipsychotic medication, which the 2015 study flagged as complicating the interpretation of movement symptoms, had been prescribed to 31.5% of the autistic group. Accounting for it "reduced but did not fully attenuate the association"^[7]. Parkinson's was still rare in absolute terms, but the authors concluded that "a heightened awareness of long-term neurological conditions" in autistic people "may be warranted"^[7].

In a 2025 study by US researchers of 379 autistic adults aged 40 to 83, 119 (almost a third) screened positive for parkinsonism symptoms. They reported lower quality of life, more memory problems, poorer sleep and more depression symptoms, a pattern the authors say "has been largely neglected"^[8]. The overlap shows up from the other direction too. A study of 330 people aged over 50 in Kolkata, India, found higher autistic traits in both a Parkinson's group and a group with other motor disorders, both recruited through a tertiary neurology centre, than in typically ageing controls. In exploratory analyses the pattern was clear in men but absent in women^[9].

Dementia diagnoses are more common, most clearly alongside an intellectual disability

Three large US insurance-claims studies have looked at dementia. All three rest on public-insurance claims for already-diagnosed people, so their figures may not generalise. The first examined Medicaid beneficiaries aged 30 to 64 in 2008–12, an age range where any dementia counts as early-onset. Over five years, 4.04% of autistic adults without an intellectual disability had a dementia diagnosis. So did 5.22% of those with both autism and an intellectual disability, compared with 0.97% of adults with neither diagnosis (and 7.10% of those with an intellectual disability but no autism). Even after adjusting for known risk factors, dementia was diagnosed more often in both autistic groups than in the general population (adjusted hazard ratios 1.96 and 2.89)^[10].

A follow-up study linked Medicaid and Medicare records for 114,582 autistic adults aged 30 and over (2014–16). A dementia diagnosis was recorded for 8.03% of those without an intellectual disability and 8.88% of those with one. For people older than 64 the figures were 35.12% and 31.22%. With no comparison group and what they call a "circumscribed focus on insurance beneficiaries", the authors call the findings "hypothesis-generating", but say the data "highlight the importance of health policy efforts for the growing ASD population at risk for or affected by dementia"^[11].

The most detailed comparison so far was published in 2026. It followed 9,201 autistic and 18,356 non-autistic Medicare beneficiaries aged 65 and over (2013–21), matched on demographics and on known dementia risk factors. During follow-up, 25.7% of the autistic group and 11.1% of the comparison group were diagnosed with a neurocognitive disorder such as dementia. After adjustment, autistic older adults had a 20% higher risk overall and 46% higher among those with an intellectual disability. For autistic older adults without an intellectual disability, the risk was not significantly different from their peers (subhazard ratio 1.04)^[12]. Among people with high blood pressure, autistic older adults' risk was about double their peers' (subhazard ratio 2.04, against 1.09 among those without it); high cholesterol, depression and type 2 diabetes showed the same pattern. The authors conclude that risk factors "may impact the autistic population differently", and point to "the need for early screening and tailored prevention strategies". They caution that the findings "may not generalise to younger or undiagnosed autistic populations"^[12].

These studies differ in ages, periods and comparison groups, so they are not one trend, and all count recorded rather than clinically confirmed diagnoses. The 2026 report of an international expert summit on intellectual disability and dementia, held in Toronto in 2023, concluded that dementia prevalence here "appears to be influenced by co-occurring intellectual disabilities, particularly Down syndrome". It added that the relationship between autism and cognitive decline "remains a complex and underexplored area of research"^[13].

Mental health needs do not retire at 65

In the Netherlands, a study of up to 344 autistic and non-autistic adults aged 19 to 79, all with an IQ above 80 and recruited largely through mental health services (so, the authors note, rates may be overestimates), found that 79.0% of the autistic adults had met the criteria for at least one psychiatric condition during their lives, against 48.8% of the comparison group. Depression and anxiety were the most common^[14]. Autistic adults aged 55 to 79 met the criteria less often than younger autistic adults, "despite marked psychological distress". Only 2% of them met the criteria for social anxiety, against 21% of younger autistic adults. The authors caution this "could be due to a cohort effect"^[14]. In the US Medicare claims data above, with the same caveats, mood disorders were recorded for 35.9% of autistic older adults vs 9.1% of peers, and anxiety disorders for 37.2% vs 8.8%^[4].

Loneliness is part of this picture. In the UK PROTECT study, which follows adults over 50 through online questionnaires, the 672 of 9,979 participants aged 50 to 97 (6.7%) who scored above a screening cut-off for high autistic traits reported more depression, anxiety, post-traumatic stress, loneliness and social isolation than other participants. This screen measures traits, not a diagnosis, which few participants had. The high-traits group were also more likely to report thoughts of suicide more than once (29% vs 16%). The researchers found the link ran partly through mental health difficulties and social isolation, and called for "targeted and individually tailored interventions for people on the autism spectrum across the lifespan"^[3]. These are needs that support and services can address. Our article on autism and suicide research covers the evidence on prevention, and what helps.

The research gap: 0.4% of autism studies

A 2022 review counted 212 articles on autism in older age. Since 2012 this research had grown by 392%, faster than research on children (196%). Yet older adults still accounted for "only 0.4% of published autism studies over the past decade", and the most studied topics were cognition, the brain and genetics^[2]. A UK study of older autistic people's use of services found that "research and service provision for older people has generally ignored older autistic people, including their particular sensory, communication, and other needs"^[15].

There are gaps within the gap. The 2026 Medicare dementia study notes that "most studies of neurocognitive disorders in autism include only those without ID"^[12]. Most of the large datasets are American insurance records, and some findings rest on screening tools rather than diagnosis. Autistica, the UK autism research charity, has run priority-setting work with a community advisory group of autistic people aged 50 and over, starting from the admission that "we don't know enough about how age-related changes may intersect with an autistic person's support needs in later life"^[16].

What the evidence asks of us

None of these changes depends on waiting for perfect data.

• Diagnosis at every age. The English researchers call for better access to adult diagnostic services^[1]. With most older autistic people undiagnosed, that has to include people in their sixties, seventies and beyond.
• Prevention and screening built for autistic older adults. The dementia gap widened where high blood pressure, high cholesterol, depression and diabetes were present, which is why the authors call for "early screening and tailored prevention strategies"^[12]. An international Think Tank of autistic self-advocates, families, clinicians and researchers, held in Vancouver in 2023, named neurology, cardiometabolic care, bone health, gut health, cancer screening, pain management and palliative care as priorities. It called for "advancing standards for screening and increased training and professional development" as urgently needed^[17].
• Neurological awareness, including prescribing. Parkinson's keeps appearing across the studies, and antipsychotic exposure explains part of that, not all^[7]. Services and researchers should track both.
• Services that adapt. Older autistic people's own recommendations include training "developed and taught by (older) autistic people", booking by email and online forms, information in writing before appointments, and extra time to respond^[15]. Our article on healthcare barriers for autistic adults sets out the wider evidence.
• Research that includes older autistic people, including those with an intellectual disability and those diagnosed late or never, from more countries than the US and UK, and co-produced with autistic people aged 50 and over^[2][16].

More research is collected in our Autism & Health research library.

Language: this piece uses identity-first language ("autistic people"), the preference of most autistic-led organisations, and uses clinical terms such as "autism spectrum disorder" only when naming a study or diagnostic category.

Why we're publishing this

Health Insurance UK is a commercial health-insurance resource, not a charity and not a campaign. We compiled this evidence because a generation of autistic people is reaching later life with health needs that research and services have barely begun to see. The autistic people, families and autistic-led organisations pressing for better care deserve the figures clean, sourced and in one place, ready for a commissioner, a memory-clinic lead or a funder. The case belongs to them. Our part is to say plainly what the data shows: more long-term conditions, mostly undiagnosed, and almost entirely left out of the research.

How to read this data

Almost all of these figures come from observational studies of insurance claims, GP records or national registers. They show associations, not causes, and count recorded diagnoses, which depend on who was assessed and how. Because many older autistic people are undiagnosed, diagnosed groups may include more people with high support needs, and some autistic people will sit unrecognised in the "non-autistic" comparison groups, which may weaken the differences found^[12]. Odds, hazard, subhazard and incidence rate ratios are different measures, and each study has its own ages, years and comparison group, so they should not be read as a single trend. The England projections are exploratory and date from 2018; the PROTECT findings use a trait screen, not diagnosis; and several Parkinson's studies are small. The US figures come from Medicare and Medicaid claims; their authors caution they may not generalise to undiagnosed autistic people or future generations. The large datasets are mostly from the US, with register data from Sweden and smaller studies from the UK, the Netherlands, Australia and India. Evidence from low- and middle-income countries is almost absent.

Use this data

Free to cite with attribution to Health Insurance UK. Charities, campaigners and journalists are welcome to reuse these figures and charts. For the underlying figures as a spreadsheet, get in touch.

Important: This article summarises published research for general information. It is not medical advice and cannot be used to diagnose, treat or predict anything about an individual. If you have concerns about your own or someone else's health, please speak to a qualified health professional.

Sources

1. O'Nions E, Petersen I, Buckman JEJ, Charlton R, Cooper C, Corbett A, et al. Autism in England: assessing underdiagnosis in a population-based cohort study of prospectively collected primary care data. The Lancet Regional Health – Europe, 2023. europepmc.org/article/MED/37090088
2. Mason D, Stewart GR, Capp SJ, Happé F. Older age autism research: a rapidly growing field, but still a long way to go. Autism in Adulthood, 2022. europepmc.org/article/MED/36605971
3. Nuzum E, Medeisyte R, Eshetu A, Hoare S, Corbett A, Ballard C, et al. Autistic traits and suicidality in midlife and old age: investigating mediating effects of mental health and social connectedness. Nature Mental Health, 2026. europepmc.org/article/PMC/PMC12890584
4. Hand BN, Angell AM, Harris L, Carpenter LA. Prevalence of physical and mental health conditions in Medicare-enrolled, autistic older adults. Autism, 2020;24(3):755–764. europepmc.org/article/PMC/PMC7433648
5. Croen LA, Zerbo O, Qian Y, Massolo ML, Rich S, Sidney S, Kripke C. The health status of adults on the autism spectrum. Autism, 2015. europepmc.org/article/MED/25911091
6. Starkstein S, Gellar S, Parlier M, Payne L, Piven J. High rates of parkinsonism in adults with autism. Journal of Neurodevelopmental Disorders, 2015. europepmc.org/article/MED/26322138
7. Yin W, Reichenberg A, Schnaider Beeri M, Levine SZ, Ludvigsson JF, Figee M, Sandin S. Risk of Parkinson disease in individuals with autism spectrum disorder. JAMA Neurology, 2025. europepmc.org/article/MED/40423965
8. Wallace GL, Said AJ, McQuaid GA. Elevated parkinsonism symptoms in autism during middle and older adulthood are linked with psychosocial, physical health, and mental health outcomes. Autism Research, 2025. europepmc.org/article/MED/39569641
9. Dey I, Pathak S, Chakrabarty S, Belmonte MK, Choudhury S, Kumar H, Chakrabarti B. Elevated autistic features in Parkinson's disease and other motor disorders. Autism, 2025. europepmc.org/article/MED/40856532
10. Vivanti G, Tao S, Lyall K, Robins DL, Shea LL. The prevalence and incidence of early-onset dementia among adults with autism spectrum disorder. Autism Research, 2021;14(10):2189–2199. europepmc.org/article/MED/34378867
11. Vivanti G, Lee WL, Ventimiglia J, Tao S, Lyall K, Shea LL. Prevalence of dementia among US adults with autism spectrum disorder. JAMA Network Open, 2025. jamanetwork.com/journals/jamanetworkopen/fullarticle/10.1001/jamanetworkopen.2024.53691
12. Nikahd M, Hyer M, Wolf B, Patterson B, Bishop L, Hand B. Risk of dementia and related neurocognitive disorders among autistic and non-autistic older adults: role of established risk factors. Age and Ageing, 2026;55(2):afag015. academic.oup.com/ageing/article/55/2/afag015/8460036
13. Janicki MP, McCallion P, Jokinen N, Larsen FK, Mughal D, Palanisamy V, et al. Autism and dementia: a summative report from the 2nd International Summit on Intellectual Disabilities and Dementia. Journal of Autism and Developmental Disorders, 2026. europepmc.org/article/MED/40327233
14. Lever AG, Geurts HM. Psychiatric co-occurring symptoms and disorders in young, middle-aged, and older adults with autism spectrum disorder. Journal of Autism and Developmental Disorders, 2016. europepmc.org/article/PMC/PMC4860203
15. Hersh M, Mery P, Dawson M. Older autistic people, access and experiences of services, and the factors that affect this. International Journal of Environmental Research and Public Health, 2024;21(11):1535. europepmc.org/article/PMC/PMC11593569
16. Autistica. Autism and Ageing (research project). Autistica, 2021. autistica.org.uk/our-research/research-projects/autism-and-ageing
17. Nicholas DB, Shafai F, Edelson SM, Bal V, Nelson H, Lawson W, et al. Advancing care priorities for health and quality of life among older adults in the autism and/or intellectual disabilities communities: proceedings of an international Think Tank. BMC Proceedings, 2025. europepmc.org/article/PMC/PMC12168249