The BDNF gene has a common single nucleotide polymorphism causing a valine to methionine amino acid substitution at residue 66 (Val66Met) and Met allele carriers have been shown to exhibit reduced synaptic activity and greater cognitive decline compared to Val/Val homozygotes (Miyajima et al., 2008; Lim et al., 2013). This evidence concerns the gene BDNF and Mental deterioration.