Clinical, demographic, and neuropsychological data (mean ± SD) for the two PD groups and the HC group.

Differential effects between the three groups are reported (single-factor ANOVA and t tests for two independent groups).Abbreviations: DRT: dopamine replacement therapy; HC: healthy controls; H&Y: Hoehn and Yahr; HC: healthy controls; MADRS: Montgomery-Asberg Depression Rating Scale; MCST: Modified Wisconsin Card Sorting Test; MMSE: Mini-Mental State Examination; PD: Parkinson's disease; S&E: Schwab and England; SD: standard deviation; STAI: State-Trait Anxiety Inventory; TMT: Trail Making Test.§Comparisons (single-factor ANOVA) were performed between the early PD ON, advanced PD and HC groups.#Comparisons (t test for two independent groups) were performed between the early PD ON and advanced PD groups.##Comparisons (t test for two independent groups) were performed between the early PD OFF and advanced PD groups.* Statistically significant (p