Abstract: This invention pertains to development of a new animal model for Parkinson's Disease (PD) and to the discovery that elevated monoamine oxygenase B (MOA-B) expression and/or activity is a strong prognostic indicator for the disease. Accordingly, in certain embodiments, methods are provided for identifying a mammal at risk for Parkinson's disease. The methods typically involve determining level of expression or activity of monoamine oxidase B (MAO-B) in a sample from the mammal wherein an elevated level of MAO-B expression and/or activity as compared to a control (reference) is an indicator that the mammal has an increased likelihood of developing Parkinson's disease.