title: A systematic review and secondary data analysis of the interactions between the serotonin transporter 5-HTTLPR polymorphism and environmental and psychological factors in eating disorders.
abstract: To summarize and synthesize the growing gene x environment (GxE) research investigating the promoter region of the serotonin transporter gene (5-HTTLPR) in the eating disorders (ED) field, and overcome the common limitation of low sample size, by undertaking a systematic review followed by a secondary data meta-analysis of studies identified by the review.
  
  
  
  A systematic review of articles using PsycINFO, PubMed, and EMBASE was undertaken to identify studies investigating the interaction between 5-HTTLPR and an environmental or psychological factor, with an ED-related outcome variable. Seven studies were identified by the systematic review, with complete data sets of five community (n = 1750, 64.5% female) and two clinical (n = 426, 100% female) samples combined to perform four secondary-data analyses: 5-HTTLPR x Traumatic Life Events to predict ED status (n = 909), 5-HTTLPR x Sexual and Physical Abuse to predict bulimic symptoms (n = 1097), 5-HTTLPR x Depression to predict bulimic symptoms (n = 1256), and 5-HTTLPR x Impulsiveness to predict disordered eating (n = 1149).
  
  
  
  Under a multiplicative model, the low function (s) allele of 5-HTTLPR interacted with traumatic life events and experiencing both sexual and physical abuse (but not only one) to predict increased likelihood of an ED and bulimic symptoms, respectively. However, under an additive model there was also an interaction between sexual and physical abuse considered independently and 5-HTTLPR, and no interaction with traumatic life events. No other GxE interactions were significant.
  
  
  
  Early promising results should be followed-up with continued cross-institutional collaboration in order to achieve the large sample sizes necessary for genetic research.
authors.affiliation: Department of Psychological Sciences, The University of Melbourne, Parkville 3010, Australia. Electronic address: vanja@rozenblat.net.
authors.forename: Vanja
authors.initials: V
authors.lastname: Rozenblat
authors.affiliation: Department of Psychological Sciences, The University of Melbourne, Parkville 3010, Australia.
authors.forename: Deborah
authors.initials: D
authors.lastname: Ong
authors.affiliation: School of Psychology, Deakin University, Geelong 3220, Australia.
authors.forename: Matthew
authors.initials: M
authors.lastname: Fuller-Tyszkiewicz
authors.affiliation: Department of Psychology, Estonian Centre of Behavioural and Health Sciences, University of Tartu, Tartu 50410, Estonia.
authors.forename: Kirsti
authors.initials: K
authors.lastname: Akkermann
authors.affiliation: Social, Genetic, and Developmental Psychiatry Research Centre, Institute of Psychiatry, King's College, London SE5 8AF, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Collier
authors.affiliation: Behavioural Science Institute, Radboud University Nijmegen, 6500 HE Nijmegen, The Netherlands.
authors.forename: Rutger C M E
authors.initials: RCME
authors.lastname: Engels
authors.affiliation: Department of Psychiatry, University Hospital of Bellvitge - IDIBELL, 08907, Spain; CIBER Fisiopatologia Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Fernandez-Aranda
authors.affiliation: Department of Psychology, Estonian Centre of Behavioural and Health Sciences, University of Tartu, Tartu 50410, Estonia.
authors.forename: Jaanus
authors.initials: J
authors.lastname: Harro
authors.affiliation: Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Radboud University Medical Centre, Department of Cognitive Neuroscience, 6525 EZ Nijmegen, The Netherlands.
authors.forename: Judith R
authors.initials: JR
authors.lastname: Homberg
authors.affiliation: Department of Child and Adolescent Psychiatry, Medical University of Vienna, 1090 Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Karwautz
authors.affiliation: Department of Psychology, Estonian Centre of Behavioural and Health Sciences, University of Tartu, Tartu 50410, Estonia.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Kiive
authors.affiliation: Department of Psychology, Michigan State University, East Lansing, MI 48824-1116, United States.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Klump
authors.affiliation: Department of Psychology, University of Wisconsin-Milwaukee, WI, United States.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Larson
authors.affiliation: Department of Psychology, Michigan State University, East Lansing, MI 48824-1116, United States.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Racine
authors.affiliation: Eating Disorders Continuum, Douglas Institute, Montreal, Canada; Psychiatry Department, McGill University, Montreal, Canada.
authors.forename: Jodie
authors.initials: J
authors.lastname: Richardson
authors.affiliation: Eating Disorders Continuum, Douglas Institute, Montreal, Canada; Psychiatry Department, McGill University, Montreal, Canada.
authors.forename: Howard
authors.initials: H
authors.lastname: Steiger
authors.affiliation: Department of Psychology, University of Nebraska-Lincoln, Lincoln, NE 68588, United States.
authors.forename: Scott F
authors.initials: SF
authors.lastname: Stoltenberg
authors.affiliation: Behavioural Science Institute, Radboud University Nijmegen, 6500 HE Nijmegen, The Netherlands.
authors.forename: Tatjana
authors.initials: T
authors.lastname: van Strien
authors.affiliation: Department of Child and Adolescent Psychiatry, Medical University of Vienna, 1090 Vienna, Austria.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Wagner
authors.affiliation: The Institute of Psychiatry, Psychology, and Neuroscience, King's College, London SE5 8AF, United Kingdom.
authors.forename: Janet
authors.initials: J
authors.lastname: Treasure
authors.affiliation: Department of Psychological Sciences, The University of Melbourne, Parkville 3010, Australia.
authors.forename: Isabel
authors.initials: I
authors.lastname: Krug
mesh_terms: D001068:Feeding and Eating Disorders / Q000235:genetics* / Q000523:psychology*; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D006801:Humans; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins
keywords: 5-HTTLPR; Bulimia nervosa; Eating disorders; Gene-environment interaction; Meta-analysis; Systematic review