Patients were included if they were between the ages of 35 and 80, had a confirmed diagnosis of Parkinson disease and had a diagnosis for the Diagnostic and Statistical Manual of Mental Disorders 5th ed. (DSM-V) of Depressive disorders.
Patients were excluded if they had cognitive impairment (Mini-Mental State Examination [MMSE] less than 27), had a psychotic disorder and suicidal thought or attempt, use of antipsychotics, anticholinergics, dopamine agonists and other psychological therapies, use of metoclopramide, methyldopa, methylphenidate, reserpine, flunarizine, cinnarizine, or amphetamine derivatives within the past 3 months, a history of malignant melanoma; or previous deep brain stimulation surgery, pregnant or lactating women, use of contraception and were “off” for greater than 50% of the day.