An interaction between SIMD and polygenic risk was observed when Mill Hill Vocabulary was analysed (SAGE: β = 0.026, P = 0.01; Yale‐Penn: β = 0.024, P = 0.02) (Table 3) but this did not withstand correction for multiple testing. When the meta‐analysed score was tested a significant interaction was also found (β = 0.031, P = 0.004), and this remained significant after correction for multiple testing. For illustrative purposes, Fig. 2 shows the association between PGRS and Mill Hill Vocabulary in each quintile of SIMD rank. The impact of alcohol dependence polygenic risk on Mill Hill Vocabulary scores appears most pronounced in individuals in the most socially deprived quintile (1), whereas in the least socially deprived quintile (5), polygenic risk has almost no effect on Mill Hill Vocabulary performance (Fig. 2).
