title: Stressful life events and the brain-derived neurotrophic factor gene in bipolar disorder.
abstract: BACKGROUND
  Gene-environment interactions may contribute to the high heritability of bipolar affective disorder. The aim of the present study was to examine the interplay between the BDNF Val(66)Met polymorphism and stressful life events (SLEs) in bipolar disorder.
  
  
  METHODS
  A total of 1085 participants were recruited, including 487 bipolar I cases and 598 psychiatrically healthy controls. All participants completed the List of Threatening Life Events Questionnaire; bipolar subjects reported the events that occurred 6 months leading up to their worst manic episode and 6 months prior to their worst depressive episode, controls recorded events experienced 6 months before interview. The sample was genotyped for the BDNF Val(66)Met polymorphism (rs6265).
  
  
  RESULTS
  Both Met carrier BDNF genotype and SLEs were significantly associated with the worst depressive episode of bipolar disorder. For the worst depressive episodes the effects of SLEs were also significantly moderated by BDNF genotype (gene x environment interaction).
  
  
  CONCLUSIONS
  The use of a self report questionnaire to measure stressful life events may increase recall inaccuracies, therefore caution should be taken when interpreting these results.
  
  
  CONCLUSIONS
  The findings of this study highlight the importance of the interplay between genes and the environment in bipolar disorder.
authors.affiliation: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK. georgina.hosang@kcl.ac.uk
authors.forename: Georgina M
authors.initials: GM
authors.lastname: Hosang
authors.forename: Rudolf
authors.initials: R
authors.lastname: Uher
authors.forename: Robert
authors.initials: R
authors.lastname: Keers
authors.forename: Sarah
authors.initials: S
authors.lastname: Cohen-Woods
authors.forename: Ian
authors.initials: I
authors.lastname: Craig
authors.forename: Ania
authors.initials: A
authors.lastname: Korszun
authors.forename: Julia
authors.initials: J
authors.lastname: Perry
authors.forename: Federica
authors.initials: F
authors.lastname: Tozzi
authors.forename: Pierandrea
authors.initials: P
authors.lastname: Muglia
authors.forename: Peter
authors.initials: P
authors.lastname: McGuffin
authors.forename: Anne E
authors.initials: AE
authors.lastname: Farmer
mesh_terms: D000328:Adult; D000483:Alleles; D001714:Bipolar Disorder / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D004843:Epistasis, Genetic / Q000235:genetics*; D005260:Female; D006580:Genetic Carrier Screening; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D012931:Social Environment
chemical_list: D019208:Brain-Derived Neurotrophic Factor