Cognitive performance was evaluated using the following instruments: Mexican adaptations of Beck and Steer's anxiety [25] and depression [26] inventories; our brief neuropsychological (NEUROPSI)[27,28] and computerized neuropsychological test batteries, and the Mini-mental Parkinson State Examination (MMPSE)[29]. Patients reported on their quality of life as related to their daily living activities; physical and mental well-being (health status); cognition and communication, and one summary index.