Gene-environment interplay between peer rejection and depressive behavior in children.
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).
Brendgen
Mara
M
Department of Psychology, University of Quebec at Montreal, Québec, Canada. Brendgen.Mara@uqam.ca
Vitaro
Frank
F
Boivin
Michel
M
Girard
Alain
A
Bukowski
William M
WM
Dionne
Ginette
G
Tremblay
Richard E
RE
Pérusse
Daniel
D
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