Increased anticholinergic medication use in middle-aged and older autistic adults and its associations with self-reported memory difficulties and cognitive decline.

Many commonly used prescription and over-the-counter medicines have potent anticholinergic (AC) effects. Among older adults, AC medications are associated with cognitive impairment and risk for cognitive disorders, including Alzheimer's disease. Collectively, the impact of AC medications is known as anticholinergic cognitive burden (ACB). Because of the high rates of co-occurring medical and psychiatric conditions, autistic adults may have high AC exposure and, thus, may experience elevated ACB. However, no research has characterized AC exposure or examined its associations with cognitive outcomes in autistic adults. Autistic adults (40-83 years) recruited via Simons Powering Autism Research's (SPARK) Research Match service self-reported their medication use (N = 415) and memory complaints (N = 382) at Time (T)1. At T2, 2 years later, a subset of T1 participants (N = 197) self-reported on decline in cognition. Medications were coded using two scales of AC potency. A high proportion (48.2%-62.9%, depending upon the AC potency scale) of autistic adults reported taking at least one medication with AC effects, and 20.5% to 26.5% of autistic adults reported clinically-relevant levels of AC medication (potency ≥3). After controlling for birth-sex, and age, hierarchical linear regression models showed total ACB scores and AC potency values of ≥3 predicted greater memory complaints. Logistic regression models showed that AC medicines at T1 were associated with self-reported cognitive decline at follow-up 2 years later. Understanding AC medications-including potentially earlier AC polypharmacy-and their impacts on cognition (e.g., dementia risk) in autistic adults is warranted.