Background: Previous research suggests that personality traits, particularly novelty seeking (NS), increase the risk of substance abuse. One possible explanation to account for this association relates to common genetic factors. The aim of this study was to examine whether allelic variants of the dopamine D4 receptor gene (DRD4) are associated with alcohol use in adolescents and to determine the extent to which these links are mediated by NS.
Methods: Three hundred three adolescents (144 male participants, 159 female participants, approximately 15 years old) from a high-risk community sample completed self-report questionnaires measuring alcohol intake and temperament (Junior Temperament and Character Inventory [JTCI]). DNA was genotyped for the DRD4 exon III polymorphism.
Results: Male participants carrying the 7-repeat allele of DRD4 drank higher maximum amounts of alcohol per occasion and had greater lifetime rates of heavy drinking than male participants without this allele. Higher levels of NS were associated with higher alcohol intake in both genders. Multiple regression analyses support the role of NS in mediating the relationship between DRD4 and heavy drinking in male adolescents but not in female adolescents.
Conclusions: These findings extend previous work highlighting the significance of personality traits as a mediating factor between genetic susceptibility and substance use during the period of early experimental use.