Recently, we observed an epistatic relationship between the BDNF Val66Met polymorphism and Aβ deposition in which BDNFMet healthy individuals showed a faster rate of hippocampal atrophy and episodic memory decline than BDNFVal homozygotes, but only if they had abnormally high Aβ [8]. Here, BDNF is linked to hippocampal atrophy.