Objective: The aims of this study were to evaluate the impact of the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism on several psychological characteristics in a group of Greek University students and to explore putative interactions with the serotonin-transporter-linked polymorphic region (5-HTTLPR) and serious past adverse experiences.
Methods: A total of 224 students were genotyped and classified as (a) carriers or noncarriers of the Met allele of the BDNF Val66Met polymorphism and (b) carriers or noncarriers of the S or Lg alleles (S′) of the 5-HTTLPR polymorphism. Students were evaluated using a battery of standard psychological tests and answered questionnaires on serious past adverse experiences.
Results: The Val/Val BDNF genotype was associated with higher scores in several psychopathological dimensions. When the effect of the BDNF Met allele was examined in relation to 5-HTTLPR, it was restricted to S′ noncarriers. Among these students, BDNF Met allele carriers had lower scores compared with noncarriers. The effects of the Met allele on the S′ allele noncarriers in the anxiety and phobic anxiety dimensions were more pronounced among individuals who had reported no serious life adversities.
Conclusion: There may be a protective role of the BDNF Met allele in several psychopathological features and it is suggested that some of these effects are moderated by 5-HTTLPR.