Two studies (Seeman et al., 2005; Van Gerven et al., 2012) found the strongest cognitive decline in highly education APOE-ε4 carrier, while other studies showed no significant statistical interaction (Kalmijn et al., 1997) or a decreasing association of APOE-ε4 with cognitive decline as education increases (Shadlen et al., 2005). Here, APOE is linked to Mental deterioration.