Hong CT, et al. - In patients with early-stage Parkinson's disease (PD), researchers ascertained if antiparkinsonism anticholinergics (AAs) increase the risk of dementia via data from the National Health Insurance Research Database of Taiwan. Based on the propensity score, they selected and matched 30,740 patients with newly diagnosed PD. To examine dementia risk, conditional Cox proportional regression analysis was used. In early-stage PD patients, exposure to AAs for ≥6 months positively interacted with conventional risk factors for dementia (age, hypertension, diabetes, and hyperlipidemia) creating an increased risk of dementia, according to subgroup analyses. In patients with early-stage PD, greater exposure to AAs increased the risk of dementia, which was thought to be a result of the class effect of anticholinergics. Even though AAs have a therapeutic effect on PD patients, it should be prescribed with caution.