The proposed path model provided a good fit to the data (see Figure 3) and study variables accounted for approximately 7% of the variance in past year cigarette use (included SNPs collectively accounted for 1.3% of the variance). There was no evidence for direct effects of the examined polymorphisms on past year cigarette use (see Figure 3). Findings indicate a mediating role of behavioral control in the association between GABRA6 rs3811995 and externalizing behavior; those with the CC genotype had lower rates of behavioral control. In turn, behavioral control negatively predicted externalizing behavior. This indirect effect was significant (0.54, 95% BBCI = 0.25 – 0.97) with 42.3% of the total effect of GABRA6 rs3811995 on externalizing behavior operating through behavioral control. Behavioral control also had a significant direct effect on cigarette use. The indirect effect of GABRA6 rs3811995 on cigarette use via behavioral control was significant (0.04, 95% BBCI = 0.01 – 0.09) with 27.3% of the total effect of GABRA6 rs3811995 on cigarette use operating through behavioral control.
