We did not find any significant loci in the much smaller AFR or EAS analyses, nor could we precisely estimate SNP-heritability or genetic correlations due to the limited power. The lack of diversity in genetic data is unfortunate, as nicotine dependence and tobacco use disorder are leading contributors to mortality in worldwide populations (Le Foll et al., 2022; Reitsma et al., 2021). A related limitation was our inability to conduct sex- and birth cohort-stratified analyses; rates of tobacco use vary markedly according to both sex and birth cohort, which may in turn modify the extent to which genetic liability influences risk for DSM-NicDep. Amassing more genetic datasets with DSM-derived nicotine dependence would enable such valuable analyses.
