Revisiting the association between REM sleep behavior disorder and Parkinson's disease progression.

This study challenges the assumption that REM sleep behavior disorder (RBD) is a marker of severe Parkinson's disease (PD) progression. Using two-sample Mendelian randomization, we found no causal link between PD progression and RBD. Interestingly, RBD exhibited a potential protective effect on motor and composite PD progression, warranting further investigation.