title: Stressful life events and the serotonin transporter gene (5-HTT) in recurrent clinical depression.
abstract: BACKGROUND
  An interaction between recent stressful life events (SLEs) and a serotonin transporter promoter polymorphism (5-HTTLPR) in depression has been inconsistently reported. Some of this variability may be due to a previous focus on sub-clinical depression, inclusion of individuals at the lower or upper ends of the age-span, or assumptions concerning the degree of dominance of the low expressing allele. Therefore, a large sample of patients with recurrent clinically diagnosed depression and controls screened for absence of depression was utilised to examine the moderating effect of each 5-HTTLPR genetic model on the association between SLEs and severe depressive episodes.
  
  
  METHODS
  A sample of 1236 recurrent unipolar depression cases and 598 age-matched, never psychiatrically ill controls completed the List of Threatening Experiences Questionnaire to assess the number of SLEs experienced in the 6 months prior to the most severe depressive episode (cases) or interview (controls). DNA extracted from blood or cheek swabs was genotyped for the short (s) and long (l) alleles of 5-HTTLPR.
  
  
  RESULTS
  A greater number of SLEs were reported by cases than controls and this held across all genotypic groups. There was no main effect of 5-HTTLPR on depression and no evidence of interaction between total SLEs and any of the 5-HTTLPR genetic models. The results were the same for men and women.
  
  
  CONCLUSIONS
  Utilisation of retrospective self-reported SLEs may have reduced the accuracy of the findings and the cross-sectional design prevents causal inference.
  
  
  CONCLUSIONS
  This study failed to find evidence of gene-environment interplay in recurrent clinical depression.
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK. Electronic address: helen.2.fisher@kcl.ac.uk.
authors: Helen L
authors: HL
authors: Fisher
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Sarah
authors: S
authors: Cohen-Woods
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Georgina M
authors: GM
authors: Hosang
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Rudolf
authors: R
authors: Uher
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Georgia
authors: G
authors: Powell-Smith
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Robert
authors: R
authors: Keers
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Maria
authors: M
authors: Tropeano
authors: Barts and The London School of Medicine and Dentistry, Queen Mary University of London - Centre for Psychiatry, London, UK.
authors: Ania
authors: A
authors: Korszun
authors: Department of Psychiatry, School of Clinical & Experimental Medicine, University of Birmingham, Birmingham, UK.
authors: Lisa
authors: L
authors: Jones
authors: Department of Psychological Medicine & Neurology, Cardiff University School of Medicine, Cardiff, UK.
authors: Ian
authors: I
authors: Jones
authors: Department of Psychological Medicine & Neurology, Cardiff University School of Medicine, Cardiff, UK.
authors: Mike
authors: M
authors: Owen
authors: Department of Psychological Medicine & Neurology, Cardiff University School of Medicine, Cardiff, UK.
authors: Nick
authors: N
authors: Craddock
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Ian W
authors: IW
authors: Craig
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Anne E
authors: AE
authors: Farmer
authors: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK.
authors: Peter
authors: P
authors: McGuffin
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000235:genetics*; D005260:Female; D006801:Humans; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012008:Recurrence; D012189:Retrospective Studies; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins