Anticholinergic drugs may raise dementia risk in adults with ASD and intellectual disabilities

Adults with autism spectrum disorder (ASD) and intellectual disability who take high doses of anticholinergic (AC) medications may be at elevated risk for cognitive decline, according to a new study. AC drugs, used to treat a wide range of medical problems, inhibit the action of the neurotransmitter acetylcholine. Long-term use of these drugs is associated with declines in cognition in elderly individuals, particularly in those taking larger doses.

In a 2024 study specific to autism, Goldie McQuaid and colleagues found that middle-aged and older adults with ASD who took higher amounts of AC medications reported experiencing an elevated rate of memory problems and cognitive decline. Participants in that study did not have intellectual disability.

In their new research, McQuaid and her team studied autistic adults with legally authorized representatives, in order to focus on individuals with both ASD and intellectual disability. Analyzing data on 512 individuals between 18 and 68 years of age, they report, “The majority (66.41%) of autistic adults were taking at least one AC medication and 31% were taking clinically-meaningful levels of these medications.” After controlling for age and birth sex, the researchers found that “greater potency of AC medications was associated with both caregiver-reported memory challenges and behavioral/cognitive changes associated with cognitive decline.”

Noting that individuals with ASD and intellectual disability are at elevated risk for dementia, the researchers say, “AC medication use may represent a potential modifiable risk factor for decrements in cognition in autistic adults with higher support needs.” They recommend that clinicians evaluate the medication regimens of individuals with ASD and intellectual disability to determine the potential impact of AC drugs on cognition. “Further,” they say, “it may be appropriate to begin such evaluations earlier in the lifespan, given the potential for earlier and thus more prolonged exposure to potent AC medications in this population.”

Citations

“Characterization of anticholinergic medication use and its associations with everyday memory problems and cognitive decline in autistic adults with higher support needs,” Goldie A. McQuaid, Nancy Raitano Lee, and Gregory L. Wallace, Autism Research, August 13, 2026 (free online). Address: Goldie McQuaid, [email protected].