The mediating role of novelty seeking in the association between the type 4 dopamine receptor gene polymorphism and cigarette-smoking behavior

We examined the relationship between type 4 dopamine receptor gene and cigarette-smoking behavior and the mediating role of the temperamental dimension novelty seeking (NS). Participants were 150 smoking and non-smoking high and low NS scorers from a randomized population-based sample of 20-35 year old men and women. We genotyped the participants for a 48 base-pair repeat polymorphism in the DRD4 gene. Novelty seeking was assessed by the Temperament and Character Inventory. The two- and five-repeat alleles were significantly more common in the group of current smokers than others (odds ratio 2.53, 95% CI 1.06-6.01). After controlling for the effect of novelty seeking on smoking behavior, the relationship dropped substantially, being no longer statistically significant.