Young adulthood is a critical developmental period for the progression from initiation to more advanced smoking milestones (NSDUH, 2015). This study links variation in a genome-wide significant gene, CYP2A6, with the development of smoking behaviors in two independent samples of European American young adults. Using specific CYP2A6 polymorphisms, we calculated a nicotine metabolism metric, which has been previously shown to account for approximately 70% of the variance in metabolism of orally administered nicotine to cotinine in European Americans (Bloom et al., 2012; Bloom et al., 2011). Our primary finding is that slower nicotine metabolism is associated with an elevated risk of developing nicotine dependence among young adult daily smokers, adding important insight into the role of variation in CYP2A6 across stages of smoking development, as illustrated in Figure 3.
