title: Interaction between serotonin transporter promoter and dopamine receptor D4 polymorphisms on decision making.
abstract: Appropriate decision making is an important brain function to maintain our lives. The Iowa gambling task (IGT) is a tool for decision making under ambiguity. The aims of this study were to evaluate the influence of serotonin transporter linked polymorphic region (5-HTTLPR) and dopamine receptor D4 (DRD4) polymorphisms and their interaction on IGT performance. One hundred fifty-nine normal subjects were involved in this study. All subjects performed the IGT and were genotyped for the triallelic 5-HTTLPR and DRD4 48 bp uVNTR polymorphisms. After controlling for gender, age, and impulsiveness, there were no main effects of 5-HTTLPR and DRD4 gene polymorphisms on total IGT score. However, there was a significant effect on the interaction between 5-HTTLPR and DRD4 on total IGT score. In the presence of the 5-HTTLPR S'S' (SS+SL(G)+L(G)L(G)), subjects with the DRD4 2R+ (2 repeat carrier) had higher total IGT score compared to those with the DRD4 2R-. In contrast, in the absence of the 5-HTTLPR S'S', subjects with the DRD4 2R- had higher total IGT score than those with the DRD4 2R+. When we divided IGT scores into the first and second half of trials, the 5-HTTLPRxDRD4 interaction effects were stronger in the second half block (decision under risk) than in the first half block (decision under ambiguity). In conclusion, the DRD4 genotypes might influence decision-making performance differently according to the background genotypes of 5-HTTLPR.
authors.affiliation: Department of Psychiatry and Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea. harayeon@yuhs.ac
authors.forename: Ra Yeon
authors.initials: RY
authors.lastname: Ha
authors.forename: Kee
authors.initials: K
authors.lastname: Namkoong
authors.forename: Jee In
authors.initials: JI
authors.lastname: Kang
authors.forename: Yang Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Se Joo
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003657:Decision Making / Q000502:physiology*; D005260:Female; D005715:Gambling; D005838:Genotype; D006801:Humans; D007175:Impulsive Behavior / Q000235:genetics; D008297:Male; D009483:Neuropsychological Tests; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011569:Psychiatric Status Rating Scales; D050638:Receptors, Dopamine D4 / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D055815:Young Adult
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins; D050638:Receptors, Dopamine D4