Rasagiline for the Symptomatic Treatment of Fatigue in Parkinson's Disease

Inclusion Criteria: 1. A clinical diagnosis of idiopathic PD by a movement disorders specialist. All subjects will be diagnosed using the UK Brain Bank criteria (Hughes et al., 1992). 2. Age between 40-85 years. 3. Able to sign and understand informed consent; and cognitively able to carry out the procedures in the study 4. Stable on all PD medications for at least 30 days; and psychotropic medications for at least 90 days. 5. Treatment naïve subjects who are appropriate candidates to begin MAO-inhibitor monotherapy as treatment for their PD may also be included in this study. 6. Fatigue Severity Scale ≥ 36 (KRupps et al., 1989) Exclusion Criteria: 1. Clinically significant medical disease that is associated independently with fatigue (e.g. significant cardiac or pulmonary disease, anemia, obstructive sleep apnea, liver or kidney failure). 2. History of neurological illnesses other than PD or a history of a significant head trauma (involving unconsciousness). 3. Evidence of secondary or atypical parkinsonism as suggested by the presence of any of the following: 1) history of stroke(s), 2) exposure to toxins or neuroleptics, 3) history of encephalitis, 4) neurological signs of upper motor neuron disease, cerebellar involvement, supranuclear gaze palsy, or significant orthostatic hypotension. 4. MRI or CT scan with significant evidence of brain atrophy or other abnormalities (e.g. lacunar infarcts or iron deposits in the putamen. 5. Clinical diagnoses of dementia; or an MMSE score of \< 25. 6. Unstable, newly diagnosed, or newly treated (i.e. less than 3 months) major psychiatric disorder such as depression or anxiety 7. Beck's Depression Inventory score \>14. 8. Current or prior placement of Deep Brain Stimulator. 9. Currently taking an MAO-B inhibitor or medications which are used as fatigue treatments, including amantadine, modafinil, methylphenidate, atomoxetine or other psychostimulants. 10. Previously taken an MAO-B inhibitor for more than 2 weeks. 11. Hypersensitivity to rasagiline or its products 12. On mirtazapine, venlafaxine, regular use of compounds with vasoconstrictors, tramadol, meperidine, propoxyphene, dextromethorphan, St. John's wort, cyclobenzaprine 13. On omeprazole, ciprofloxacin or drugs that are metabolized through CYP1A2