title: The effect of depression, BDNF gene val66met polymorphism and gender on serum BDNF levels.
abstract: OBJECTIVE
  To determine the effect of BDNF gene val66met polymorphism on serum BDNF levels in drug-free patients with major depressive disorder (MDD) and healthy subjects, that differ by gender.
  
  
  METHODS
  Sixty-six drug-free patients (19 males+47 females) with non-psychotic MDD and fifty-six healthy controls (18 males+38 females) were recruited. Three-way ANOVA was employed to analyze the effect of mental health status, met-carriage and gender on Hamilton Depression Rating Scale (HDRS) scores and serum BDNF levels, by using the MIXED Procedure (SAS).
  
  
  RESULTS
  Patients had a lower serum BDNF level than healthy subjects (22.47 vs. 27.49; p<0.0001). Met-carrier patients had a higher HDRS score than Val homozygote's (25.99 vs. 22.99, p<0.02). Serum BDNF level for met-carrier subjects (patients+controls) was lower than Val homozygote subjects (23.08 vs. 26.87; p<0.002). However, there were no effects of two-way interactions of met-carriage and mental health status on HDRS scores and serum BDNF levels. There was no gender effect on HDRS scores in the patients. Overall, male subjects (patients+controls) had a higher serum BDNF level than female subjects (26.87 vs. 23.08; p<0.002). However, there were no effects of two-way interactions of gender with mental health status and met-carriage on serum BDNF levels.
  
  
  CONCLUSIONS
  We replicated the previous findings of lower serum BDNF levels during depression and in females. In addition, we found that met-carriage had an effect in reducing serum BDNF levels, regardless of gender and depression. Further animal and human studies with a larger sample size should investigate whether BDNF val66met polymorphism could alter brain and serum BDNF levels.
authors: Ataturk University School of Medicine, Department of Psychiatry, 25240 Erzurum, Turkey. erolozan@gmail.com
authors: Erol
authors: E
authors: Ozan
authors: Hamza
authors: H
authors: Okur
authors: Cağdaş
authors: C
authors: Eker
authors: Ozlem D
authors: OD
authors: Eker
authors: Ali Saffet
authors: AS
authors: Gönül
authors: Nurten
authors: N
authors: Akarsu
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood* / Q000235:genetics*; D003865:Major Depressive Disorder / Q000097:blood* / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011569:Psychiatric Status Rating Scales; D017422:Sequence Analysis, DNA; D012727:Sex Characteristics
chemical_list: D019208:Brain-Derived Neurotrophic Factor