of metabolism (CYP2A6 *1/*1) progressed in degree of nicotine dependence (increase in Fagerstrom Test for Nicotine Dependence >1) more quickly than slow metabolizers (CYP2A6*9, CYP2A6*12, CYP2A6*2, or CYP2A6*4) (Audrain-McGovern et al., 2007). As seen in other adolescent and adult smokers, cigarette consumption was lower among slow than normal metabolizers (Audrain-McGovern et al., 2007). Differences in ages, heaviness of smoking, or methods of assessment of nicotine dependence may have contributed to these differing results on smoking acquisition in youth. Alternatively, it is possible that early in smoking, slow metabolizers may convert to dependence more rapidly, but the rate of increase in level of dependence and rate of smoking may increase more rapidly for the normal metabolizers relative to slow metabolizers. Additional research is necessary to sort out the role of the CYP2A6 gene in smoking adoption.
