title: BDNF gene polymorphism, cognition and symptom severity in a Brazilian population-based sample of first-episode psychosis subjects.
abstract: OBJECTIVE
  To investigate the influence of brain-derived neurotrophic factor (BDNF) gene variations on cognitive performance and clinical symptomatology in first-episode psychosis (FEP).
  
  
  METHODS
  We performed BDNF val66met variant genotyping, cognitive testing (verbal fluency and digit spans) and assessments of symptom severity (as assessed with the PANSS) in a population-based sample of FEP patients (77 with schizophreniform psychosis and 53 with affective psychoses) and 191 neighboring healthy controls.
  
  
  RESULTS
  There was no difference in the proportion of Met allele carriers between FEP patients and controls, and no significant influence of BDNF genotype on cognitive test scores in either of the psychosis groups. A decreased severity of negative symptoms was found in FEP subjects that carried a Met allele, and this finding reached significance for the subgroup with affective psychoses (p < 0.01, ANOVA).
  
  
  CONCLUSIONS
  These results suggest that, in FEP, the BDNF gene Val66Met polymorphism does not exert a pervasive influence on cognitive functioning but may modulate the severity of negative symptoms.
authors: Department of Psychiatry, Universidade de São Paulo, São Paulo, Brazil.
authors: Eduardo
authors: E
authors: Martinho
authors: Leandro
authors: L
authors: Michelon
authors: Adriana M
authors: AM
authors: Ayres
authors: Marcia
authors: M
authors: Scazufca
authors: Paulo R
authors: PR
authors: Menezes
authors: Maristela S
authors: MS
authors: Schaufelberger
authors: Robin M
authors: RM
authors: Murray
authors: Teresa M
authors: TM
authors: Rushe
authors: Homero
authors: H
authors: Vallada
authors: Geraldo
authors: G
authors: Busatto Filho
mesh_terms: D000293:Adolescent; D000328:Adult; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D001938:Brazil; D003071:Cognition / Q000502:physiology*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011618:Psychotic Disorders / Q000235:genetics*; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor