The effect of pramipexole on depressive symptoms in Parkinson's disease.

Depression is a common occurrence in patients with Parkinson's disease (PD). Pramipexole is a dopamine agonist that has been used to treat both motor and non-motor symptoms associated with PD. We conducted a study to elucidate the effect of pramipexole on each of the depressive symptoms as assessed by the Zung Self-Rating Depression Scale (SDS). Twenty patients with PD were treated with pramipexole 1.5-3.0 mg daily for 2-3 months. The SDS and the Unified Parkinson Disease Rating Score (UPDRS) were measured in each subject before and after the treatment. Both the SDS and the UPDRS decreased significantly after treatment with pramipexole. Individual assessment of each item in the SDS indicated that "crying spell", "confusion", "psychomotor retardation", "emptiness", and "dissatisfaction" symptoms improved significantly following treatment, while "depressed affect", "decreased libido", "constipation", and "indecisiveness" symptoms were worse after the treatment. As the symptom of "indecisiveness" did not respond to treatment, it might be an essential symptom in patients with PD.