Stressful life events and the brain-derived neurotrophic factor gene in bipolar disorder.
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.
Hosang
Georgina M
GM
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
Uher
Rudolf
R
Keers
Robert
R
Cohen-Woods
Sarah
S
Craig
Ian
I
Korszun
Ania
A
Perry
Julia
J
Tozzi
Federica
F
Muglia
Pierandrea
P
McGuffin
Peter
P
Farmer
Anne E
AE
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
D019208:Brain-Derived Neurotrophic Factor