Epidemiology of Alzheimer Disease and Related Dementia Among Medicare and Medicaid Enrolled Autistic Adults, 2011-2019.
Autistic adults on public insurance show dementia rates four times higher in eight years, starting almost a decade sooner than typical.
01Research in Context
What this study did
Tewolde et al. (2025) tracked Alzheimer disease and related dementia in autistic adults. They used Medicare and Medicaid billing codes from 2011 to 2019. All participants were 30 or older and publicly insured.
What they found
The share of autistic adults with dementia nearly quadrupled. It rose from 2% to 8% in just eight years. Average age at first diagnosis was 59, earlier than the general population.
How this fits with other research
Bishop et al. (2023) showed sleep problems and antipsychotic use raise heart risk in the same adult group. Together the papers flag a pattern: treatable mid-life issues pile up fast.
Deserno et al. (2017) found bright autistic adults still lag in daily living skills. Salina’s team now shows those adults also face earlier brain decline. The double gap sharpens the need for life-long supports.
Schaaf et al. (2015) warned that 25-50% of high-functioning clients lost the ASD label under DSM-5. If fewer high-support adults carry the code today, Salina’s 8% dementia rate may under-count the true burden.
Why it matters
You may soon serve autistic clients who forget steps, wander, or lose speech in their fifties. Start teaching simple memory aids, exercise, and sleep routines now. Track changes yearly and refer early for cognitive work-ups.
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02At a glance
03Original abstract
Alzheimer's disease and related dementias (ADRD) are burdensome and lethal conditions that have been hypothesized to be related to autism through shared genetic etiologies and environmental risk factors. Our objective was to use longitudinal Medicaid and Medicare data to describe the epidemiology of ADRD in publicly insured autistic adults. We used all claims and encounters from 2011 to 2019 to identify autism and ADRD. We calculated prevalence, incidence, age at onset, and created survival curves. There were 90,229 autistic adults ≥ 30 years of age and enrolled for at least 1 year in Medicaid and/or Medicare and 267 ADRD cases. Prevalence of ADRD was 2.09% (95% CI: 1.99%, 2.20%) in 2011 and 8.11% (95% CI: 7.92%, 8.30%) in 2019. Mean age at ADRD onset was 59.3 years (SD: 14.2). Mean age among men was 58.3 years (SD: 13.8) and 61.0 years among females. Incidence of ADRD was higher in autistic adults with intellectual disability with no difference by sex. ADRD is a prevalent condition in middle- and older-aged adults identified with autism in the Medicaid and Medicare system. Understanding the diagnostic process and phenotype of ADRD will be important to improve identification and treatment.
Autism research : official journal of the International Society for Autism Research, 2025 · doi:10.1111/jgs.15638