MONDAY, Nov. 2, 2026 (HealthDay News) -- Middle-aged and older adults with autism are more likely to have parkinsonism than adults without autism or intellectual disability (ID), according to a study published online Oct. 24 in Autism.
Gregory L. Wallace, Ph.D., from George Washington University in Washington, D.C., and colleagues estimated the prevalence and incidence of parkinsonism among middle-aged and older adults with autism. The analysis used individually linked Medicaid and Medicare health care claims data from 2017 to 2019 from nearly 57 million adults (aged 45 years and older) with autism only, ID only, autism + ID, and a control sample.
The researchers found that compared with the control sample (1.57 percent), there was a highly elevated prevalence of co-occurring Parkinson disease-related diagnoses in the other groups (autism only: 3.83 percent; ID only: 4.32 percent; autism + ID: 4.86 percent). This heightened prevalence persisted when excluding individuals prescribed antipsychotic medications. The age-standardized incidence or risk for newly documented co-occurring parkinsonism was highest in those with autism + ID, followed by those with autism only and those with ID only, whether examining broader or narrower definitions of parkinsonism (excluding secondary parkinsonism), and far outpaced the incidence seen in the control sample.
"This raised incidence suggests that the increased co-occurrence of these conditions is not primarily a byproduct of preexisting motoric symptoms in autism that appear earlier in development; rather, these parkinsonism motoric symptoms are emerging and being flagged by health care providers during middle and older adulthood at increased rates for autistic adults," the authors write.
