What is the evidence that autistic individuals are more likely to get an age-related disease? A 2021 study published in Autism Research (1) based on an analysis of Medicaid records in the United States found that autistic individuals were 2.6 times more likely to be diagnosed with early-onset dementia (occurring before age 65) than nonautistic individuals. More recently, this conclusion has been expanded (2) to all forms of dementia based on both Medicaid and Medicare records, with a dementia prevalence of ~33% in elderly autistic adults 65 years and older. The findings suggested that autistic individuals were prone to a “markedly elevated prevalence of identified dementia diagnoses.” Similarly, an early study with a small number of participants (3) suggested that older autistic individuals might also be more prone to Parkinson’s disease. This has recently been confirmed and extended in a very large-scale study conducted in Sweden (4), which analyzed medical records from 2,278,565 individuals. They found that Parkinson’s disease occurred in 438 of 2,226,611 nonautistic individuals (1.3 cases/100,000) but 24 of 51,954 autistic individuals (3.9 cases/100,000). Why having autism increases the chances of being diagnosed with one of these age-related, neurodegenerative diseases is entirely unknown. An important first step to getting a clearer understanding will be examining the brains of autistics for the telltale signs of dementia or Parkinson’s disease, such as plaques or tangles in the brain, to determine if they are similar or different from nonautistic individuals.
The Importance of Studying Aging in Autism
The last three decades have seen enormous growth in research on the causes and trajectories of autism. There has been tremendous progress in identifying genetic risk factors and understanding much about the early developmental features of autism. But, with a worldwide population of autistics numbering 60-75 million and perhaps 20 million who are older than 40, it becomes increasingly urgent to understand what to expect from aging autistics. Concern has been raised by large-scale epidemiological studies that indicate that autistics have increased rates of major psychiatric disorders and virtually all medical conditions (5). One outcome of this is the increased mortality of autistic individuals (6) who die, on average, 10-15 years earlier than nonautistic individuals.
How Are Researchers Studying the Aging Autistic Brain?
Multiple research groups from around the world have begun conducting longitudinal studies to understand the potentially unique cognitive aging trajectories in autistic adults. Longitudinal studies follow the same people over time, which is the gold-standard approach for understanding how aging impacts specific populations, but this approach can take many years to form conclusions. Further, only a handful of these research groups are also conducting longitudinal brain imaging, which will help researchers determine the causes of cognitive decline. For example, at Arizona State University, Dr. Braden’s Autism Brain Aging Laboratory reports that it “is among the first to study age-related changes in adults with autism spectrum disorder (ASD) through neuropsychological evaluations and multi-modal neuroimaging.”(7) Multi-modal neuroimaging means using different approaches to understand how aging changes the way the brain functions and is structurally built. Using this approach, the research lab is working to “comprehensively describe age-related cognitive and brain changes in autistic adults and develop behaviorally and neurobiologically informed interventions for autistic adults across the lifespan.”(7)
The Aging Autistic Brain Has Not Yet Been Studied at the Cellular and Molecular Levels
Beyond imaging, the only way to study the biological causes of autism at the cellular and molecular level is with postmortem brain tissue. For that reason, there is a call to action for autistic people and their loved ones to learn about and consider brain donation as part of their end-of-life planning. The Autism BrainNet (8) program, funded by the Simons Foundation, facilitates the collection, processing, storage, and distribution of donated postmortem brain tissue to advance autism and related neurodevelopmental disorders research worldwide. The program acts as a bridge between the autism community and the worldwide community of scientists who are dedicated to a greater understanding of autism and related neurodevelopmental disorders through the gift of brain donation.
A single gifted brain can support hundreds of studies and be viable for decades under the program’s rigorous tissue processing and preservation protocol. Researchers working on autism and related neurodevelopmental disorders can request access to Autism BrainNet postmortem brain tissue and associated clinical data, with the understanding that their research findings will be shared back with the community to augment knowledge in autism.
How Does Brain Donation Work?
Brain donation and organ donation are not the same. Organ donation is used for transplantation, and brain donation is only used for research, though donors can contribute to both programs! Importantly, you cannot opt into a brain donation registry like Autism BrainNet at the Department of Motor Vehicles.
To minimize the stress of decision-making when a loved one is in crisis, it is highly recommended to learn about the brain donation process in advance. Visiting the Autism BrainNet website is the first step, as it shares the stories of donor families, as well as details about the donation process and what families can expect.
Autism BrainNet has a 24/7, no-obligation telephone helpline to answer families’ questions and/or arrange for a brain donation once a decision has been made (877-333-0999). Autism BrainNet clinical staff will work with the legal next of kin to obtain the needed authorization for donation and manage the entire donation process. There is no cost to families working with Autism BrainNet, and brain donation does not interfere with a family’s autopsy or funeral plans.
Why Should You Champion Autism Research?
Better diagnostic approaches combined with ongoing research to understand the underlying causes and manifestations of autism and related neurodevelopmental disorders will contribute to decreased disability and improved quality of life. The success of Autism BrainNet depends on our partnership with autistic individuals and their families who care for them.
If you want to learn more about Autism BrainNet, please visit our website at AutismBrainnet.org.
B. Blair Braden, PhD, is an Associate Professor and Director of the Speech and Hearing Science PhD Program as well as Director of the Autism and Brain Aging Laboratory at Arizona State University’s College of Health Solutions. David G. Amaral, PhD, is the Scientific Director of Autism BrainNet and a UC Davis Distinguished Professor at the UC Davis MIND Institute and the Department of Psychiatry and Behavioral Sciences.
References
- Vivanti G, Tao S, Lyall K, Robins DL, Shea LL (2021): The prevalence and incidence of early-onset dementia among adults with autism spectrum disorder. Autism Res. 14:2189-2199.
- Vivanti G, Lee WL, Ventimiglia J, Tao S, Lyall K, Shea LL (2025): Prevalence of Dementia Among US Adults With Autism Spectrum Disorder. JAMA Netw Open. 8:e2453691.
- Starkstein S, Gellar S, Parlier M, Payne L, Piven J (2015): High rates of parkinsonism in adults with autism. J Neurodev Disord. 7:29.
- Yin W, Reichenberg A, Schnaider Beeri M, Levine SZ, Ludvigsson JF, Figee M, et al. (2025): Risk of Parkinson’s Disease in Individuals With Autism Spectrum Disorder. JAMA Neurol.
- Croen LA, Zerbo O, Qian Y, Massolo ML, Rich S, Sidney S, et al. (2015): The health status of adults on the autism spectrum. Autism. 19:814-823.
- Hirvikoski T, Mittendorfer-Rutz E, Boman M, Larsson H, Lichtenstein P, Bolte S (2016): Premature mortality in autism spectrum disorder. Br J Psychiatry. 208:232-238.
- Autism and Aging Research Lab, Arizona State University. Last accessed on 6-10-25 at https://sites.google.com/asu.edu/autismandbrainaginglab/our-research?authuser=0
- Amaral DG, Anderson MP, Ansorge O, Chance S, Hare C, Hof PR, et al. (2018): Autism BrainNet: A network of postmortem brain banks established to facilitate autism research. Handb Clin Neurol. 150:31-39.
