IV) Finally, no strong confounding of tobacco smoking at the polygenic level in the CUD GWAS was observed. This was evaluated using the iPSYCH CUD GWAS as training for generating CUD-PRS in deCODE. The score explained more of the variance and was associated with a higher effect size for CUD risk (R2=0.24%; OR=1.17) than was found for tobacco smoking (R2=0.10%, OR=1.07) (Supplementary Table 10).
