and a s.d. of 1 such that the βs reported are standardized. The variance explained by PRS was calculated by multiplying the PRS by its regression coefficient. This value was divided by the variance of the phenotype analysed to give a coefficient of determination between 0 and 1.38 As 5 traits were tested for their association with alcohol consumption PRS, Bonferroni correction for PRS analyses required a P-value of 0.01 (0.05/5) as the threshold for statistical significance.
