Anticholinergic Burden in People With Intellectual Disability

BACKGROUND: Individuals with intellectual disability (ID) experience high rates of multimorbidity and psychotropic prescribing, placing them at greater risk of anticholinergic burden (ACB), which has been associated with adverse cognitive and physical health outcomes. However, data on ACB among people with an ID attending specialist mental health services remain limited. METHODS: A retrospective chart review was conducted for all adults with an ID (N = 159) attending a specialist mental health service. Demographic, clinical and prescribing data were extracted from clinical records. ACB was determined using the online ACB Calculator. Rates of psychiatric and physical health comorbidity and prescribing were examined. RESULTS: Elevated ACB was common, with 65% of service users recording clinically significant scores. ACB was higher in females and those in residential services and positively correlated with age and total medication burden but did not differ according to ID level. Polypharmacy was present in 57% of service users, and antipsychotics were the most frequently prescribed psychotropic medication (82%). Individuals with Down syndrome demonstrated lower ACB scores than those without. In multivariate analyses, the number of prescribed medications and antipsychotics independently predicted clinically significant ACB. CONCLUSIONS: Adults with an ID attending specialist mental health services experience substantial exposure to anticholinergic medications within the context of multimorbidity and polypharmacy. Elevated ACB appears to be driven by overall medication burden and psychotropic prescribing, particularly antipsychotic use. Routine assessment of ACB alongside individual-reported experiences and clinician-rated outcomes should form part of regular medication review processes to identify potentially modifiable prescribing risks and support safer pharmacological management. Future research should examine whether interventions that reduce ACB improve subjective, clinician-rated and broader health outcomes in ID.