Persistent anticholinergic drug exposure, but not benzodiazepine use, increase dementia risk.

Researchers from The Netherlands have examined the association between use of benzodiazepines and anticholinergic agents, and the risk of dementia. Using a prospective cohort model assessing community-dwelling older people, 3526 people aged 70 to 78 years without dementia were recruited from 116 family medicine practices. Anticholinergic drug exposure was assessed using the anticholinergic cognitive burden score. Participants were evaluated for dementia every two years, and this assessment was supplemented by information from electronic health records and the National Death Registry. The median length of follow-up was 6.7 years, during which time dementia developed for 233 people (7%). 6% of people using benzodiazepines developed dementia compared to 7% amongst nonusers [HR 0.71, 95% CI 0.58–1.07]. Persistent usage of benzodiazepines at baseline and after 2-year follow-up did not substantially alter the point-estimate (HR 0.60, 95% CI 0.34–1.10). The use of any anticholinergic drug was not associated with incident dementia (HR 1.01, 95% CI 0.50–1.10), but the risk of being diagnosed with dementia was significantly elevated for those with persistent drug use with a high anticholinergic cognitive burden score (HR 1.95, 95% CI 1.13–3.38) – this association was driven by antidepressant or antipsychotic drug use, raising the possibility of confounding by indication. Refer to the original study here.