Abstract
Apolipoprotein E (APOE) ε4 is a genetic risk factor for Alzheimer's disease (AD). Social support may confer protection against cognitive decline even in the presence of APOE ε4. We examined the relationship among APOE ε4 allele(s) carrier status, social support (overall and sub-sources), and cognition in 115 older adults (72.24 ± 8.29 years; 71.3% female). APOE ε4 carrier status moderated social support's effect on cognition, F(1, 106) = 5.08, p = 0.03, ΔR(2 )= 0.02. Among APOE ε4 carriers, as social support increased, cognitive functioning improved (β = 0.19, p = 0.03). This relationship was not found for APOE ε4 non-carriers, highlighting that socio-ecological influences may interact with genetic factors to influence later-life cognition.