title: Alterations of serum levels of brain-derived neurotrophic factor (BDNF) in depressed patients with or without antidepressants.
abstract: BACKGROUND
  Because researchers have reported that antidepressants increase the expression of brain-derived neurotrophic factor (BDNF) in the rat hippocampus, we investigated whether serum BDNF levels may be used as a putative biological marker for major depressive disorders (MDD).
  
  
  METHODS
  We measured serum BDNF in the following three groups: antidepressant-naive patients with MDD (n = 16), antidepressant-treated patients with MDD (n = 17), and normal control subjects (n = 50). Patients were evaluated using the Hamilton Rating Scale for Depression (HAM-D). Serum BDNF was assayed with the sandwich ELISA method.
  
  
  RESULTS
  We found that serum BDNF was significantly lower in the antidepressant-naive group (mean, 17.6 ng/mL; SD, 9.6) than in the treated (mean, 30.6 ng/mL; SD, 12.3; p =.001) or in the control group (mean, 27.7 ng/mL; SD, 11.4; p =.002). There was a significant negative correlation (r = -.350, z = -2.003, p =.045) between serum BDNF and HAM-D scores in all patients. In a preliminary examination, reduced BDNF values of three drug-naive patients recovered to basal levels after antidepressant treatment.
  
  
  CONCLUSIONS
  Our study suggests that low BDNF levels may play a pivotal role in the pathophysiology of MDD and that antidepressants may increase BDNF in depressed patients.
authors.affiliation: Department of Psychiatry, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Shimizu
authors.forename: Kenji
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Naoe
authors.initials: N
authors.lastname: Okamura
authors.forename: Kaori
authors.initials: K
authors.lastname: Koike
authors.forename: Naoya
authors.initials: N
authors.lastname: Komatsu
authors.forename: Chikara
authors.initials: C
authors.lastname: Kumakiri
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakazato
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Shinoda
authors.forename: Sin-ichi
authors.initials: S
authors.lastname: Okada
authors.forename: Masaomi
authors.initials: M
authors.lastname: Iyo
mesh_terms: D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood* / Q000187:drug effects; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000097:blood* / Q000188:drug therapy*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000928:Antidepressive Agents; D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor