Socio-demographic characteristics moderate the association between DRD4 and Novelty seeking

The association between dopamine receptor D4 (DRD4) gene polymorphism and the temperament dimension of Novelty seeking (NS) has recently been questioned. We tested whether childhood socio-demographic characteristics moderated this association. A population-based sample of children (n = 2149) and their parents was analyzed in 1980 in terms of socio-economic circumstances and residential setting. In 1997, the NS temperament was measured, and subjects in the low and high ends of the distribution (n = 150) were genotyped for DRD4 exon III polymorphism. An association between two- or five-repeat alleles of the DRD4 polymorphism and high NS scores was observed in the subjects with higher educated mothers, a higher annual household income, and living in an urban residential setting (OR’s 3.9, 95% CI’s = 1.45–27.3) 17 years prior to the NS assessment. These findings were not explained by gender, age, or proximal process of child-rearing that, according to a prior report, have been shown to moderate the association. Socio-demographic characteristics did not moderate the association between the DRD4 seven-repeat allele and NS. These results provide further evidence of gene–environment interaction in NS, and suggest that environmental characteristics in the childhood may moderate the association between DRD4 polymorphisms and NS.