Publication

One-year practice effects predict long-term cognitive outcomes in Parkinson’s disease

Up to 50% of individuals with Parkinson's disease develop cognitive impairment over time; this study explores the use of 'practice effects' on neuropsychological tests as an early predictor of cognitive decline.

Author

Sofía Avila Pérez, Vincent Koppelmans, Kevin M Duff, and Marit FL Ruitenberg

Date

15 May 2025

Links

Journal of Parkinson’s Disease

In addition to the well-known motor symptoms, such as tremors and slowing of movements, many (but not all) people with Parkinson’s disease also experience cognitive problems at some point during their disease. However, predicting which individuals will develop such problems remains difficult, which can limit their access to timely and appropriate care. The present study explores an innovative approach towards predicting cognitive decline through 'practice effects' on neuropsychological tests.

Typically, people’s scores improve when taking the same cognitive test twice. These improvements are due to repeated exposure to the test material (rather than increases in cognitive functioning) and referred to as practice effects. When examining such practice effects in individuals with Parkinson's disease, we observed that they show smaller improvements compared to healthy controls. In addition, we found that those individuals with Parkinson’s disease who showed smaller practice effects were at increased risk of developing cognitive impairment or dementia in the next five years.

Overall, this study shows that practice effects can help predict future cognitive problems in people with Parkinson’s disease. Unlike expensive brain scans or invasive procedures, practice effects therefore may offer a non-invasive and cost-effective screening tool that could identify at-risk individuals before significant decline occurs. This approach could transform how we monitor cognitive health in people Parkinson's and guide early intervention strategies when they might be most effective.

Read the full publication through Journal of Parkinson’s Disease.