Reductions in protein expression of zinc transporter 3 (ZnT3) in Brodmann area 9 (which is a part of the frontal cortex) were shown to be significantly associated with elevated depression scores in patients with dementia with Lewy bodies (DLB), Parkinson disease dementia (PDD), and Alzheimer disease (AD) (Whitfield et al. 2015). This evidence concerns the gene SLC30A3 and early-onset autosomal dominant Alzheimer disease.