Association of serotonin transporter genotype with selective processing of smoking‐related stimuli in current smokers and ex‐smokers

Abstract

We sought to determine whether polymorphism in the serotonin transporter (5HTT) gene is associated with attentional bias toward smoking-related stimuli in current smokers and ex-smokers, using a modified Stroop task and an attentional blink task to measure selective processing of smoking-related stimuli. All participants attended a single testing session during which they completed the modified Stroop and attentional blink tasks to index attentional bias for smoking-related stimuli, in counterbalanced order. The experimental design included two between-subjects factors of smoking status (current smoker, ex-smoker) and 5HTT genotype (short, long). Smoking status x genotype interactions were significant on both the modified Stroop (p = .046) and the attentional blink (p = .006) tasks. On the modified Stroop task, we found a significant effect of 5HTT genotype on color-naming interference among ex-smokers (p = .018) but not current smokers (p = .989). On the attentional blink task, we found a significant effect of 5HTT genotype for current smokers (p = .028), whereas among ex-smokers this effect did not reach statistical significance, although it constituted a trend (p = .086). Our data provide tentative support for a moderating influence of 5HTT genotype on attentional bias for smoking-related stimuli in ex-smokers. This finding may account for inconsistent reports of attentional bias among ex-smokers.