Reduced striatal dopamine synthesis capacity is associated with symptoms of depression in patients with de novo unmedicated Parkinson's disease.

Previous studies have suggested that impaired striatal dopamine function might be independently related to depression in patients with Parkinson's disease (PD), but the results are not uniform. In this study, we investigated de novo unmedicated and medicated PD patients with more advanced disease using 18F-fluorodopa-PET. In unmedicated de novo patients, but not in medicated patients, higher depression scores were associated with lower striatal 18F-fluorodopa uptake. These results indicate that impaired striatal dopaminergic function in PD is related to depressive symptoms and that these effects can be observed in de novo patients without the confounding effects of advanced neurodegeneration and medications.