title: Association of the brain-derived neurotrophic factor Val66Met polymorphism with reduced hippocampal volumes in major depression.
abstract: BACKGROUND
  Brain-derived neurotrophic factor (BDNF) modulates hippocampal plasticity, which is believed to be altered in patients with major depression.
  
  
  OBJECTIVE
  To examine the effect of the BDNF Val66Met polymorphism on hippocampal and amygdala volumes in patients with major depression and in healthy control subjects.
  
  
  METHODS
  Cross-sectional comparison between patients and controls.
  
  
  METHODS
  Inpatients with major depression from the Department of Psychiatry and Psychotherapy and healthy controls from the community were recruited.
  
  
  METHODS
  The study population of 120 subjects included 60 patients with major depression and 60 healthy controls.
  
  
  METHODS
  Using a combined strategy, hippocampal and amygdala volumes were estimated on high-resolution magnetic resonance images, and genotyping was performed for the BDNF Val66Met polymorphism.
  
  
  RESULTS
  Patients had significantly smaller hippocampal volumes compared with controls (P = .02). Significantly smaller hippocampal volumes were observed for patients and for controls carrying the Met-BDNF allele compared with subjects homozygous for the Val-BDNF allele (P = .006). With respect to amygdala volumes, no significant differences between patients and controls and no significant main effects for the BDNF Val66Met polymorphism were observed.
  
  
  CONCLUSIONS
  These genotype-related alterations suggest that Met-BDNF allele carriers might be at risk to develop smaller hippocampal volumes and may be susceptible to major depression. This study supports findings from animal studies that the hippocampus is involved in brain development and plasticity.
authors.affiliation: Department of Psychiatry and Psychotherapy and Radiology, Ludwig-Maximilians University, Munich, Germany. Thomas.Frodl@med.uni-muenchen.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Frodl
authors.forename: Cornelius
authors.initials: C
authors.lastname: Schüle
authors.forename: Gisela
authors.initials: G
authors.lastname: Schmitt
authors.forename: Christine
authors.initials: C
authors.lastname: Born
authors.forename: Thomas
authors.initials: T
authors.lastname: Baghai
authors.forename: Peter
authors.initials: P
authors.lastname: Zill
authors.forename: Ronald
authors.initials: R
authors.lastname: Bottlender
authors.forename: Rainer
authors.initials: R
authors.lastname: Rupprecht
authors.forename: Brigitta
authors.initials: B
authors.lastname: Bondy
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reiser
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Möller
authors.forename: Eva M
authors.initials: EM
authors.lastname: Meisenzahl
mesh_terms: D000328:Adult; D000679:Amygdala / Q000473:pathology; D001284:Atrophy; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000235:genetics* / Q000473:pathology*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008715:Methionine / Q000235:genetics; D009473:Neuronal Plasticity / Q000235:genetics; D011110:Polymorphism, Genetic; D014633:Valine / Q000235:genetics
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D008715:Methionine; D014633:Valine