The genetics of self-reported trait impulsivity: Contribution of catecholaminergic gene variants in European ancestry individuals

Increased trait impulsivity is a core element in several mental disorders. Given the durable and consistent nature of trait impulsivity, studies have explored its relation to stable biological measures. Variation in catecholaminergic neurotransmission by genetic variants could be one of these biological substrates. Here, 905 participants of European-ancestry completed the Barratt Impulsiveness Scale–11 and were genotyped in three single nucleotide polymorphisms related to catecholaminergic neurotransmission: the DRD2/ ANKK Taq1A, the C957T DRD2 and the Val158Met of the COMT gene. We found significant main effects of Val158Met and C957T on BIS-11 score. Also, interactions with gender were significant in both SNPs with a tendency to slightly different genotype and allele associations with the BIStotal score between male and female participants. Whereas in females, higher impulsivity scores were obtained by participants with the Val158Met heterozygous genotype (Met/Val), data indicate a trend towards a higher impulsivity score in male Val-allele carriers. In the case of C957T, only a tentative association between male Tallele carriers and higher impulsivity scores in comparison to CC genotype carriers could be established. No significant associations were found between BIS-11 and Taq1A. We provide further evidence for a gender-specific implication of Val158Met and C957T in trait impulsivity