These mechanisms may explain why some previous studies reported a greater prevalence of vascular dementias in the case of increased leptin concentrations [15,26,27,28], together with the present result showing worse cognitive performance in the highest quintile of leptin compared to the intermediate quintiles of leptin (Figure 2)—notably worse episodic memory, a domain-specific cognitive function underpinned by the hippocampus. This evidence concerns the gene LEP and vascular dementia.