# Putting the pieces of the autism, brain disease puzzle together

### ASU expert says more postmortem brain examinations needed

By Scott Bordow, ASU News
July 29, 2025

Research has found a correlation between having autism and being diagnosed with a neurodegenerative disease later in life.

For example, a 2021 study published in Autism Research found through Medicaid records that autistic individuals were 2.6 times more likely to be diagnosed with early-onset dementia (occurring before the age of 65) than non-autistic individuals.

A second study in Sweden found that Parkinson’s disease occurred in every 1.3 cases out of 100,000 for non-autistic individuals, but 3.9 cases for autistic individuals.

But why does this occur?

That’s what Blair Braden, an associate professor and researcher in Arizona State University’s College of Health Solutions and director of the Autism and Brain Aging Laboratory, is trying to find out.

Braden has been studying the link between autism and neurodegenerative diseases for 11 years. She recently co-authored a paper on the subject, published in Autism Spectrum News.

ASU News talked to Braden about the paper, her studies and how postmortem brain examinations are needed to move the research forward.

Note: The following interview has been edited for length and/or clarity.

Question: Can you give an overview of your paper?

Answer: It is really just to make an audience aware of this research that suggests higher risk of neurodegenerative conditions in autistic adults. And that postmortem brain research could be a way to understand why.

But for that to happen, more people need to be willing to donate their brains after they pass.

Q: What led you to this area of research?

A: A few different things. When I was a kid, my grandparents ran a nursing home, so I spent a lot of time hanging out there. When I grew up and got interested in neuroscience, I was just always interested in aging and dementia.

My older sister, who’s 12 years older than I am, was a special education teacher, and I spent a lot of time in her classroom. That’s where I first met autistic kids.

I had done my PhD on cognitive aging and Alzheimer’s research, and my autism collaborator mentioned that no one has really researched aging and autism yet. So I started writing grants, we got a lot of funding, and I built a career out of it.

Q: What kind of research are you doing out of the Autism and Brain Aging Laboratory?

A: We have been doing a longitudinal cognitive and brain aging study in autistic adults compared to non-autistic adults. We try to find as many autistic people over the age of 40 as we can, and we bring them in to do a comprehensive MRI assessment and cognitive assessment. We try to get them to come back every two years, as well as a control group, because we can’t really learn about why one group of people are affected differently if we don’t have a control group.

Some of our folks are almost 80, so we can kind of see the rate of cognitive decline in our autism group compared to our non-autism group. And we do see in some aspects like memory, which is kind of the most concerning for Alzheimer’s disease, that our autism group on average is showing steeper declines in that domain.

Q: Do doctors or researchers have any idea why that’s the case?

A: No idea. The research heavily comes from health care records like Medicaid or Medicare, or countries like Sweden that have these like highly detailed medical records.

So when you look through thousands of files, if someone has an autism diagnosis in there and they’re 50 or 60 years old, they’re just more likely to have a dementia diagnosis than someone who doesn’t. But that tells us nothing about why, and we don’t even know if those diagnoses are entirely accurate. So it’s just the tip of the iceberg. We need to do a lot more research to figure out what’s behind it.

Q: Is there a prevailing theory among medical professionals?

A: I have a lot of theories. On face value, there’s a lot of lifestyle factors that make one at a higher risk for dementia, Parkinson's disease. Things like diet and exercise and cardiovascular health. And autistic people have more challenges in those areas than non-autistic people do. So that could just be the same things that we know create risk in a general population.

But then, we have some research in our lab that shows there could be a genetic overlap risk, and autistic people might be more likely to carry some of these Alzheimer's risk genes than non-autistic people.

Q: Why is postmortem brain examination necessary in this research?

A: Even if someone today is diagnosed with Alzheimer's disease, it's considered a probable diagnosis, and the definitive diagnosis cannot be made until you examine the brain at autopsy. So we will need to do autopsy-related brain research to make those definitive conclusions. But we do have a lot more tools that we can use while people are living that give a pretty good indication of Alzheimer's or Parkinson's pathology. Different PET imaging techniques, and even more recently different proteins in the blood that we can measure. So we're starting to do some of that research too.

Q: What’s the goal of the research?

A: The ultimate goal is to understand the unique risks autistic people might be facing when they get old. And once we know those unique risks, we can provide interventions and supports that will help autistic people live fully fulfilling lives for as long as possible.

This story originally appeared on ASU News.