Data on D1R binding are sparse, but are perhaps less relevant, given that available PET studies examining Parkinson’s disease patients typically observe no differences in striatal D1R binding compared to healthy controls.145 For Parkinson’s disease and PMR in depression, there is evidence implicating the caudate and putamen, but the role of the ventral striatum has been less well characterized. The gene discussed is DRD1; the disease is Parkinson disease.