Among EA and AA young adults, the EXT PGS was not significantly associated with P3 amplitude (βEA = −0.04, 95% CI −0.11 to 0.03; βAA = −0.01, 95% CI −0.09 to 0.08; Table 3, Fig. 1c)2. For both EA and AA young adults, sex was significantly associated with P3 amplitude such that P3 amplitude was higher among females (βEA = 0.09, 95% CI 0.05–0.13; βAA = 0.17, 95% CI 0.11–0.24; Table 3); however the EXT PGS by sex interaction term was not significant for EA or AA young adults (βEA = −0.02, 95% CI −0.07 to 0.02; βAA = −0.03, 95% CI −0.13 to 0.05; online Supplementary Table 4).
