title: Gene-environment interplay between peer rejection and depressive behavior in children.
abstract: BACKGROUND
  Genetic risk for depressive behavior may increase the likelihood of exposure to environmental stressors (gene-environment correlation, rGE). By the same token, exposure to environmental stressors may moderate the effect of genes on depressive behavior (gene-environment interaction, GxE). Relating these processes to a peer-related stressor in childhood, the present study examined (1) whether genetic risk for depressive behavior in children is related to higher levels of rejection by the peer group (rGE) and (2) whether peer rejection moderates the effect of genetic factors on children's depressive behavior (GxE).
  
  
  METHODS
  The sample comprised 336 twin pairs (MZ pairs = 196, same-sex DZ pairs = 140) assessed in kindergarten (mean age 72.7 months). Peer acceptance/rejection was measured via peer nominations. Depressive behavior was measured through teacher ratings.
  
  
  RESULTS
  Consistent with rGE, a moderate overlap of genetic effects was found between peer acceptance/rejection and depressive behavior. In line with GxE, genetic effects on depressive behavior varied across levels of peer acceptance/rejection.
  
  
  CONCLUSIONS
  An increased genetic disposition for depressive behavior is related to a higher risk of peer rejection (rGE). However, genes play a lesser role in explaining individual differences in depressive behavior in rejected children than in accepted children (GxE).
authors.affiliation: Department of Psychology, University of Quebec at Montreal, Québec, Canada. Brendgen.Mara@uqam.ca
authors.forename: Mara
authors.initials: M
authors.lastname: Brendgen
authors.forename: Frank
authors.initials: F
authors.lastname: Vitaro
authors.forename: Michel
authors.initials: M
authors.lastname: Boivin
authors.forename: Alain
authors.initials: A
authors.lastname: Girard
authors.forename: William M
authors.initials: WM
authors.lastname: Bukowski
authors.forename: Ginette
authors.initials: G
authors.lastname: Dionne
authors.forename: Richard E
authors.initials: RE
authors.lastname: Tremblay
authors.forename: Daniel
authors.initials: D
authors.lastname: Pérusse
mesh_terms: D002648:Child; D002675:Child, Preschool; D003863:Depression / Q000235:genetics* / Q000523:psychology; D004200:Diseases in Twins / Q000235:genetics* / Q000523:psychology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007206:Individuality; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008960:Models, Psychological; D010379:Peer Group; D011792:Quebec; D012059:Rejection, Psychology; D012307:Risk Factors; D012917:Social Adjustment; D012931:Social Environment; D013223:Statistics as Topic; D014429:Twins, Dizygotic / Q000235:genetics / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics / Q000523:psychology