Efficacy and Safety of Lingzhi in Patients With Early Parkinson's Disease

Inclusion Criteria: * willing and able to give informed consent * age 30 years or older at time of diagnosis of Parkinson's disease * have idiopathic Parkinson's disease, defined as: * having at least 2 of the following 4 signs: resting tremor, bradykinesia, rigidity, or postural reflex impairment, at least one of which must be resting tremor or bradykinesia * no secondary or atypical parkinsonism * asymmetric features (current signs or history of asymmetric onset) * response to L-dopa, by patient self-report * Parkinson's disease duration of no more than 5 years * receiving stable therapy of L-dopa/DCI for at least 3 months; acceptable dose range: 250 mg - 1000 mg L-dopa/DCI daily * Hoehn and Yahr stage \< 4 on stable L-dopa/DCI treatment Exclusion Criteria: * have atypical parkinsonism due to drugs, metabolic disorders, encephalitis, or other neurodegenerative diseases * have any other known medical or psychiatric condition that may compromise their participation in the study * have taken another investigational drug within 90 days of baseline * have a change in dosage of any other antiparkinsonian drug (eg, pramipexole, ropinirole, pergolide, bromocriptine, methylphenidate, anticholinergics, or amantadine) during the study or within 90 days prior to baseline * have received treatment with dopamine blocking agents (including neuroleptic agents, antiemetic agents), dopamine-depleting agents (including reserpine or tetrabenazine) within 90 days prior to baseline * do not consent to participate