Our data, in combination with a review of the literature, reveal a potential role for the VNTR variant of DRD4 in the development of depression in AD patients.
To examine if selected polymorphisms in the dopamine receptor genes DRD1, DRD2, DRD3, and DRD4 are associated with the presence of psychosis or aggressive behavior in patients with Alzheimer disease (AD).
Consistent with this hypothesis, Park, Sher, Todorov, and Heath (2011) previously reported interactions between the dopamine D4 receptor gene (DRD4) and developmentally specific environments in the etiology of AD symptoms during emerging and young adulthood.