Effects of BDNF and COMT epigenetic regulatory polymorphisms on Executive Functions in adolescents

Executive Functions (EFs) are higher-order cognitive processes required for goal-directed behaviors. Literature on the genetic basis of executive functions suggests that these functions are mediated by the modulation of dopaminergic neurotransmission. The aim of the present study was to investigate how the Brain-derived neurotrophic factor (BDNF) Val66Met and the catechol-O-methyltransferase (COMT) Val158Met polymorphisms affect Cool and Hot executive functions. A total of 48 healthy Italian preadolescents, between 8 and 14 years of age, were included in the study. Participants completed the Digit Span Test, the Tower of London, The Balloon Analogue Risk Task, and The Iowa Gambling Task (IGT). The participants who were homozygous for the Val allele for BDNF performed better on the memory task and the decision making task than Val/Met and Met/Met subjects, while those who were homozygous for the Met allele for COMT performed better on the decision-making task. Results suggest that the Val allele for BDNF and the Met allele for COMT are associated with higher performances on some tasks of EFs. The results reinforce the hypothesis that Val and Met alleles show functional changes related to high order cognitive processes both for BDNF and COMT polymorphisms.