BDNF and hippocampal atrophy: Although our analysis in ND individuals revealed that Met-allele carriers had significantly increased hippocampal atrophy, we found a significant interaction between age and baseline whole brain volume and BDNF rs6265 SNP in our combined diagnosis group, which showed that Val/Val individuals have lower whole brain volumes with increasing age compared to the Met/Met homozygotes and Met-allele carriers.