Here we provide additional support for a role of the CHRNA6 and CHRNB3 genes in mediating nicotine dependence. This study has used a population-representative sample to show that three SNPs, rs7004381, rs4950, and rs2304297 are associated with tobacco dependence. To our knowledge, this is the first study to show evidence for association of variation in CHRNA6 and CHRNB3 with dependence measured by DSM-IV symptom endorsement. Therefore, results presented here suggest that association of tobacco dependence with these genes is present using different diagnostic criteria across samples, thus strengthening the evidence that they are likely to contribute to nicotine related behaviors.
