Anticholinergic exposure was common across autistic and intellectually disabled adults, and the burden was highest when both conditions coexisted
Anticholinergic prescribing may be quietly amplifying later-life risk in adults with autism and intellectual disability. In a retrospective cohort drawn from 2017 to 2019 linked Medicare and Medicaid claims, every clinical group examined carried a heavier anticholinergic burden than non-autistic, non-ID controls, and the gradient was steepest in adults with both autism and intellectual disability. Exposure reached 92.5% in the autism-plus-ID group, 88.6% in ID-only adults, and 80.0% in autism-only adults, compared with 61.3% in controls.
The pattern matters because anticholinergic drugs are not a single medication class in practice; they are a pharmacologic burden built from many prescriptions with varying potency. As central and peripheral cholinergic signaling is dampened, older adults may face a biologic mix of impaired cognition, worsened balance, urinary symptoms, constipation, sedation, and autonomic instability. In people already living with neurodevelopmental disability, those effects can be difficult to separate from baseline communication differences or functional dependence, which makes medication review especially important.
One sentence captures the clinical problem plainly: high anticholinergic burden was the rule, not the exception.
Claims data linked higher anticholinergic potency with dementia, falls, and death
The analysis used validated algorithms to identify Alzheimer’s disease and related dementias (ADRD), falls, autism, and intellectual disability, while mortality came from Medicare and Medicaid death indicators. Investigators then examined anticholinergic exposure and interactions between potency level and diagnostic group using modified Poisson regression. The study design cannot prove causation, but it does show a consistent association across several late-life outcomes that are highly relevant to day-to-day care.
Anticholinergic medications were more frequently associated with ADRD, falls, and mortality in all three clinical groups. The relationship was stepwise: as anticholinergic potency increased, the likelihood of each adverse outcome rose as well. That dose-response pattern strengthens concern for biological plausibility, since stronger anticholinergic effects should, in theory, produce more disruption in attention, memory, gait stability, and physiologic reserve than weaker agents.
For middle-aged and older adults with autism or intellectual disability, the issue is not simply theoretical medication risk. Falls can translate into fractures, loss of mobility, emergency care, and reduced independence. Dementia adds another layer of vulnerability, especially when cognitive change may be harder to detect early in people whose communication patterns or adaptive functioning differ from the general population.
The strongest exposure signal appeared in autism plus intellectual disability
Adults with both autism and intellectual disability had the heaviest exposure burden in the cohort. Autism-only adults also had elevated exposure relative to controls, while ID-only adults sat between the autism-plus-ID group and the autism-only group. That gradient suggests that combined neurodevelopmental disability may coincide with greater prescribing of medications that carry anticholinergic activity, whether because of co-occurring psychiatric illness, sleep disturbance, gastrointestinal complaints, bladder symptoms, or other chronic health problems common in these populations.
The study also found that the associations between anticholinergic potency and negative outcomes were more prominent in the autism and/or ID groups than in controls. In practical terms, the same medication class may have a larger apparent effect in people whose neurologic reserve, communication capacity, and functional baseline already differ from those of the general older adult population. A modest decrement in attention or postural control can have outsized consequences when daily living skills are already under strain.
Ageing in autism and intellectual disability has been underexamined, and this work helps define a more concrete medication-related exposure that can be measured and potentially modified. The results do not say anticholinergic drugs alone explain elevated rates of dementia, falls, or death. They do show that the burden of these medications is widespread and tracks with poorer outcomes in a population already at elevated risk.
Sensitivity analyses tried to limit confounding by psychiatric indication
Because anticholinergic medications often travel with antidepressant and antipsychotic treatment, indication bias is a serious concern. To address that problem, the analysis repeated testing after excluding people prescribed antidepressant and/or antipsychotic medications. The associations persisted, which makes a simple explanation based only on psychiatric comorbidity less convincing.
Even so, claims-based research has well-known limits. Administrative data do not capture over-the-counter use, exact adherence, prescribing rationale, symptom severity, or the nuanced clinical tradeoffs that lead to a chosen drug. Residual confounding can remain when sicker patients are more likely to receive more medications in general. Still, the consistency of the signal across ADRD, falls, and mortality argues that anticholinergic burden deserves attention rather than dismissal.
Medication review may be a concrete target in routine care
The investigators frame anticholinergic medication exposure as one potentially modifiable risk factor for negative aging-related outcomes in autistic adults and adults with intellectual disability. That is a cautious conclusion, and an appropriate one. The data support closer review of medications with anticholinergic effects, especially when treatment goals can be met with lower-potency alternatives or nonpharmacologic approaches.
This has direct bedside implications. In an older autistic adult with recurrent falls, new memory problems, or unexplained functional decline, the medication list should be examined for cumulative anticholinergic load rather than assessed drug by drug in isolation. The same approach applies in adults with intellectual disability, where hidden medication effects may masquerade as progression of baseline disability or age-related change.
The cohort was drawn from linked Medicare and Medicaid data for adults aged 40 and older, so the findings speak to middle age as well as later life. The use of validated identification algorithms and a comprehensive anticholinergic potency scale strengthens the analysis, while the inability to share individual data reflects the constraints of CMS data use agreements rather than a flaw in the clinical question itself.
A final caution is necessary: this is a preprint, not a peer-reviewed paper, and the results should not be used as a stand-alone basis for treatment decisions. What the study does provide is a strong rationale for prospective work that can separate medication effects from comorbidity burden, measure cognitive and functional change directly, and test whether reducing anticholinergic load lowers the risk of falls, ADRD, and premature mortality in these high-risk adults.