title: Childhood problem behavior and parental divorce: evidence for gene-environment interaction.
abstract: OBJECTIVE
  The importance of genetic and environmental influences on children's behavioral and emotional problems may vary as a function of environmental exposure. We previously reported that 12-year-olds with divorced parents showed more internalizing and externalizing problems than children with married parents, and that externalizing problems in girls precede and predict later parental divorce. The aim of the current study was to investigate as to whether genetic and environmental influences on internalizing and externalizing problems were different for children from divorced versus non-divorced families.
  
  
  METHODS
  Maternal ratings on internalizing and externalizing problems were collected with the Child Behavior Checklist in 4,592 twin pairs at ages 3 and 12 years, of whom 367 pairs had experienced a parental divorce between these ages. Variance in internalizing and externalizing problems at ages 3 and 12 was analyzed with biometric models in which additive genetic and environmental effects were allowed to depend on parental divorce and sex. A difference in the contribution of genetic and environmental influences between divorced and non-divorced groups would constitute evidence for gene-environment interaction.
  
  
  RESULTS
  For both pre- and post-divorce internalizing and externalizing problems, the total variances were larger for children from divorced families, which was mainly due to higher environmental variances. As a consequence, heritabilities were lower for children from divorced families, and the relative contributions of environmental influences were higher.
  
  
  CONCLUSIONS
  Environmental influences become more important in explaining variation in children's problem behaviors in the context of parental divorce.
authors.affiliation: Department of Child and Adolescent Psychiatry, Erasmus University Medical Center-Sophia, Rotterdam, The Netherlands.
authors.forename: Sylvana
authors.initials: S
authors.lastname: Robbers
authors.forename: Floor
authors.initials: F
authors.lastname: van Oort
authors.forename: Anja
authors.initials: A
authors.lastname: Huizink
authors.forename: Frank
authors.initials: F
authors.lastname: Verhulst
authors.forename: Catharina
authors.initials: C
authors.lastname: van Beijsterveldt
authors.forename: Dorret
authors.initials: D
authors.lastname: Boomsma
authors.forename: Meike
authors.initials: M
authors.lastname: Bartels
mesh_terms: D001699:Biometry; D016022:Case-Control Studies; D002653:Child Behavior Disorders / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology*; D002675:Child, Preschool; D004243:Divorce / Q000523:psychology* / Q000706:statistics & numerical data; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D007223:Infant; D007389:Internal-External Control; D008297:Male; D008957:Models, Genetic; D009426:Netherlands; D010290:Parents / Q000523:psychology*; D011340:Problem Solving; D011569:Psychiatric Status Rating Scales; D012737:Sex Factors; D012931:Social Environment; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics