Comorbid conditions associated with Parkinson's disease: A longitudinal and comparative study with Alzheimer disease and control subjects.

Background And Objective: To study what comorbid conditions were present at baseline and 3years later in a cohort of Spanish Parkinson's disease (PD) patients, to compare comorbidity with both Alzheimer's disease (AD) and control groups and to analyze the role of comorbidity as predictor of mortality.

Methods: One hundred and forty-seven non-demented PD patients (57.1% males; 70.