Overview of participantś baseline characteristics.

HY: Hoehn & Yahr; net PANDA: Parkinson Neuropsychometric Dementia Assessment (PANDA) after subtraction of the test item Verbal Fluency (max. = 23 pt); f: female; m: male; r: right; l: left; b: bilaterally; LED: total daily levodopa equivalent dose; UPDRS III: Unified Parkinson’s Disease Rating Scale – motor score (max. = 108 pt).Values indicate the mean (± standard deviation). Values in each upper row relate to each entire group of patients. Values in the lower rows, given in brackets, relate to the subgroup of long-term diseased patients. Disease related values refer to the treatment ON condition.