title: Association of a functional BDNF polymorphism and anxiety-related personality traits.
abstract: BACKGROUND
  Converging lines of evidence point to brain-derived neurotrophic factor (BDNF) as a factor in the pathophysiology of depression. Recently, it was shown that the Val allele of the BDNF Val66Met substitution polymorphism showed a significant association with higher mean neuroticism scores of the NEO-Five Factor Inventory (NEO-FFI) in healthy subjects, and previous studies suggested the Val allele to be increased in bipolar disorder families. The association to anxiety-related traits has not been investigated so far.
  
  
  METHODS
  We tested a total of 343 unrelated subjects of German descent (171 male, 172 female, age: 39.0+/-14.6 years) who were carefully screened for psychiatric health. The self-ratable State-Trait Anxiety Inventory (STAI), which allows anxiety to be quantified as a comparatively stable personality trait, and the NEO-Five Factor Inventory (NEO-FFI) was applied.
  
  
  RESULTS
  In the trait-related anxiety score, a significant (F=3.2, df=2, p<0.042) effect of the genotype was observed with higher levels of trait anxiety in Val/Val (35.0+/-7.4) compared to Val/Met (33.4+/-6.5) and Met/Met (32.0+/-4.6) genotypes. The NEO neuroticism scores were also higher in Val/Val (29.5+/-7.0) than in Val/Met (28.4+/-6.5) or Met/Met (26.8+/-5.8) genotype, but not at a significant rate.
  
  
  CONCLUSIONS
  Our findings support the hypothesis that anxiety- and depression-related personality traits are associated with the BDNF polymorphism although the explained variance is low.
authors.affiliation: Department of Neurology, University of Tuebingen, Hoppe-Seyler-Str. 3, 72076 Tuebingen, Germany.
authors.forename: Undine E
authors.initials: UE
authors.lastname: Lang
authors.forename: Rainer
authors.initials: R
authors.lastname: Hellweg
authors.forename: Peter
authors.initials: P
authors.lastname: Kalus
authors.forename: Malek
authors.initials: M
authors.lastname: Bajbouj
authors.forename: Kirsten P
authors.initials: KP
authors.lastname: Lenzen
authors.forename: Thomas
authors.initials: T
authors.lastname: Sander
authors.forename: Dieter
authors.initials: D
authors.lastname: Kunz
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D010551:Personality / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011569:Psychiatric Status Rating Scales; D044465:White People
chemical_list: D019208:Brain-Derived Neurotrophic Factor