title: Altered declarative memory in introverted middle-aged adults carrying the BDNF val66met allele.
abstract: BACKGROUND
  The val66met polymorphism of the brain-derived neurotrophic factor gene (BDNFMet) is associated with impaired learning/memory function, affective dysregulation and maladaptive personality traits. Here, we examine the potential relationship between the BDNFMet allele, introversion and declarative memory in middle-age adults.
  
  
  METHODS
  A total of 132 middle-aged healthy adults took part in this study that included taking a blood sample for genetic profiling, a short battery of neuropsychological tests and the NEO-Five Factor Inventory (NEO-FFI), widely used to assess the Big Five personality.
  
  
  RESULTS
  Controlling for age, level of education and sex, a multiple analysis of covariance (MANCOVA) computing the effect of BDNF polymorphism on extraversion and declarative memory revealed a significant association (D1,128=4.79; p=0.03; ηp(2)=0.053). Using the Sobel Goodman Mediation Test, it was found that 25.61% of the relationship between genotype and declarative memory performance was mediated by introversion. Subsequent correlational analyses yielded a strong and significant correlation (β=0.53; p<0.001) between introversion and declarative memory specific to BDNFMet individuals.
  
  
  CONCLUSIONS
  this study highlights the pertinence of further investigating gene×personality×environment interactions to account for the significant variability that is observed in cognitive function in late life.
authors.affiliation: Department of Psychology, University of Quebec at Trois-Rivieres, Trois-Rivieres, Quebec, Canada. louis.debeaumont@uqtr.ca
authors.forename: Louis
authors.initials: L
authors.lastname: De Beaumont
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Fiocco
authors.forename: Geneviève
authors.initials: G
authors.lastname: Quesnel
authors.forename: Sonia
authors.initials: S
authors.lastname: Lupien
authors.forename: Judes
authors.initials: J
authors.lastname: Poirier
mesh_terms: D000368:Aged; D000483:Alleles; D000704:Analysis of Variance; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D004247:DNA / Q000235:genetics; D005260:Female; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D007439:Introversion, Psychological; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D010556:Personality Tests; D011110:Polymorphism, Genetic / Q000235:genetics; D011597:Psychomotor Performance / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D014888:Wechsler Scales
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D004247:DNA
keywords: Ageing; BDNF val66met; Behavioural neuroscience; Cognitive decline; Declarative memory; Extraversion; Introversion