Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism in schizophrenia is associated with age at onset and symptoms

Neurosci Lett. 2006 Jun 19;401(1-2):1-5. doi: 10.1016/j.neulet.2006.02.054. Epub 2006 Mar 14.


Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor that promotes several functions of neurons and modulates neurotransmissions. It has been reported that there are alterations of BDNF levels in schizophrenic brains and that BDNF gene expressional changes would be responsible for the etiology of schizophrenia. Recent studies have shown that a variation of BDNF gene (Val66Met polymorphism) affects the function of neurons, and is associated with several neurological and psychiatrical disorders. We investigated the relationship between BDNF Val66Met polymorphism and the onset age as well as levels of clinical symptoms in 159 of chronic schizophrenia in-patients diagnosed by DSM-IV. The mean onset ages were 27.5+/-9.5 for BDNF Val/Val, 25.5+/-7.4 for BDNF Val/Met and 22.9+/-6.0 for BDNF Met/Met and this polymorphism was significantly associated with age at onset (P=0.023). The mean Brief Psychiatric Rating Scale scores (BPRS) were significantly different among those three groups (P=0.003). No significant differences were demonstrated comparing the BDNF genotype distributions of positive and negative family history (P=0.21). Our investigation indicates that the BDNF gene Val66Met polymorphism is related to the onset age of schizophrenia and the levels of clinical symptoms that remain after long-term antipsychotic treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age of Onset
  • Aged
  • Amino Acid Substitution / genetics*
  • Antipsychotic Agents / pharmacology
  • Brain / metabolism
  • Brain / physiopathology
  • Brain Chemistry / genetics
  • Brain-Derived Neurotrophic Factor / genetics*
  • DNA Mutational Analysis
  • Drug Resistance / genetics
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease / genetics*
  • Genetic Testing
  • Genotype
  • Humans
  • Male
  • Methionine / genetics
  • Middle Aged
  • Polymorphism, Genetic / genetics*
  • Schizophrenia / drug therapy
  • Schizophrenia / genetics*
  • Schizophrenia / physiopathology*
  • Valine / genetics


  • Antipsychotic Agents
  • Brain-Derived Neurotrophic Factor
  • Methionine
  • Valine