of education and attainment (rg = 0.58–0.69). CigDay and SmkCes were most highly positively correlated with respiratory and cardiovascular diseases and cancers (rg = 0.52–0.72), highlighting their genetic link to adverse disease outcomes. Finally, DrnkWk was most strongly correlated with problematic drinking behaviours (rg = 0.52–0.70), indicating extensive overlap in the genetic architecture of DrnkWk and measures of alcohol use, problems and alcohol use disorder. This is consistent with previous findings of strong but imperfect genetic correlations (for example, rg = 0.8) between alcohol consumption and alcohol use disorder from large-scale GWAS31,32. We note, however, that genetic correlations can be difficult to interpret33,34 as they may be affected by genetic confounding, mediation effects or sampling bias.
