People with newly diagnosed Parkinson’s disease are more likely to suffer from cognitive decline if they are taking multiple medications, according to Japanese researchers.

The study enrolled 131 hospitalized patients with newly diagnosed Parkinson’s disease. Participants took a standardized test of cognitive function. The researchers compared results between groups of patients with and without polypharmacy. 

The patients in the polypharmacy group had significantly lower exam scores than patients in the non-polypharmacy group, reported corresponding author Nobuyuki Ishii, M.D., Ph.D., University of Miyazaki.

“This finding suggests that medication reduction might serve as a promising intervention to prevent the development of dementia in patients with early Parkinson’s disease,” concluded Ishii and colleagues.

The study was published in Dementia and Geriatric Cognitive Disorders.