between rs2304297 and early subjective response to tobacco in both samples studied. Each of these samples consisted of adolescents/young adults (mean ages of 18.21 ± 1.5 and 22.4 ± 1.7), as was the relatively small sample in the Greenbaum et al (2006) paper (mean age 23.3 ± 2.3), which may include individuals who are still in an “experimental” phase of smoking and haven’t yet tried to quit. The NYS sample studied here, as well as the NICSNP sample used in Saccone et al (2007) and Bierut et al (2007), include older adults (mean ages 39 ± 3 and 45 ± 8, approximated from table 6 p45 in the Saccone et al (2007) paper). Therefore, of the five samples where rs2304927 was investigated, two have found evidence for early subjective response to tobacco (Zeiger et al, 2008), two have found evidence for nicotine dependence (Saccone et al, 2007; current study), and one did not find any evidence of association (Greenbaum et al, 2006).
