title: BDNF protein levels are decreased in transformed lymphoblasts from lithium-responsive patients with bipolar disorder.
abstract: OBJECTIVE
  Brain-derived neurotrophic factor (BDNF) is a key factor in neuroplasticity and has been implicated in the affective disorders; studies have demonstrated elevated BDNF in patients taking lithium and other mood stabilizers. The objective of our study was to analyze BDNF in lithium-responsive patients with bipolar disorder (BD) to further understand the role of BDNF in the pathophysiology of BD.
  
  
  METHODS
  Using enzyme-linked immunosorbent assay, we measured transformed B lymphocytes for BDNF protein.
  
  
  RESULTS
  BDNF levels were 36% lower in lymphoblasts from patients with BD (n = 12), compared with matched control participants (n = 13), and 55% lower when compared with their unaffected relatives (n = 14). Lithium significantly decreased BDNF levels in patients with BD and healthy control participants, although BDNF levels remained lower (33%) in the BD group posttreatment.
  
  
  CONCLUSIONS
  Decreased BDNF may constitute part of the pathophysiologic process of BD in a lithium-responsive subgroup of individuals with this disease. A compensatory mechanism protecting the genetically predisposed unaffected relatives from phenotypic expression of BD is suggested.
authors.affiliation: Department of Psychiatry, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canda.
authors.forename: Michael
authors.initials: M
authors.lastname: Tseng
authors.forename: Martin
authors.initials: M
authors.lastname: Alda
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Xiujun
authors.initials: X
authors.lastname: Sun
authors.forename: Jun-Feng
authors.initials: JF
authors.lastname: Wang
authors.forename: Paul
authors.initials: P
authors.lastname: Grof
authors.forename: Gustavo
authors.initials: G
authors.lastname: Turecki
authors.forename: Guy
authors.initials: G
authors.lastname: Rouleau
authors.forename: L Trevor
authors.initials: LT
authors.lastname: Young
mesh_terms: D000328:Adult; D018692:Antimanic Agents / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood* / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D016651:Lithium Carbonate / Q000627:therapeutic use*; D008213:Lymphocyte Activation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D018692:Antimanic Agents; D019208:Brain-Derived Neurotrophic Factor; D016651:Lithium Carbonate
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