NCT00070941

Who might be able to join this trial:

• You have been diagnosed with Parkinson's disease and show at least two of these signs: shaking at rest, muscle stiffness, slowness of movement, or balance problems
• Your Parkinson's medications have stayed the same for at least 4 weeks before joining the study
• You have not taken any antidepressant or antipsychotic medications in the 30 days before joining
• You agree not to start any new medications, talk therapy, or behavioral therapy while in the trial
• You are using an acceptable form of birth control
• You are able to read and/or follow instructions given in written or spoken English
• You have enough mental clarity to understand and agree to take part (confirmed by a short memory and thinking test)

Who may not be able to join:

• You have significant heart, liver, kidney, blood, breathing, hormone, blood vessel, or other serious health conditions that study doctors consider medically relevant
• You have certain abnormal results on blood or lab tests
• You are currently pregnant or breastfeeding
• You have taken an experimental drug within the 3 months before joining
• You have used St. John's Wort or any other natural supplement known to affect mood in the 30 days before joining
• You have taken selegiline or a similar type of medication (called MAO inhibitors) within 6 weeks before joining
• You regularly take anti-anxiety medications or routinely use sleep aids (occasional use of temazepam, melatonin, or zolpidem may be allowed — confirm with trial site)
• You started any form of talk therapy or psychotherapy within the 6 months before joining
• You have a history of bipolar disorder, mania, schizophrenia, or another psychotic condition
• You have made a serious suicide attempt in the past 12 months, or are currently considered at serious risk of suicide
• You are currently using certain medications that block dopamine (such as metoclopramide or haloperidol)
• Your Parkinson's-like symptoms are caused by medications, a metabolic condition, stroke-related disease, brain infection, or another degenerative disease (rather than true Parkinson's disease)

Important: Always verify eligibility with the trial site directly before applying.