Education is strongly correlated with performance on the Mill Hill Vocabulary test and the number of years spent in education (Supporting Information Table S2) and SIMD and intelligence are genetically correlated in this sample (Marioni et al. 2014). When education and SIMD were added as covariates to the model, the association between alcohol dependence risk score and cognitive function was substantially attenuated and no longer significant for Mill Hill Vocabulary and digit symbol coding. Polygenic risk for alcohol dependence was significantly associated with verbal fluency and the effect sizes remained similar or reduced by ∼33 percent after controlling for education and SIMD (SAGE: β = −0.024, P = 0.027; Yale‐Penn: β = −0.048, P = 0.00001) (Table 1), although the SAGE score association did not withstand correction for multiple testing.
