title: Parent-child hostility and child ADHD symptoms: a genetically sensitive and longitudinal analysis.
abstract: BACKGROUND
  Families of children with attention-deficit/hyperactivity disorder (ADHD) report higher rates of conflict within the family and more negative parent-child relationships. This study aimed to test whether negative parent-child relationships have a risk effect on ADHD symptoms using two complementary designs.
  
  
  METHODS
  The first sample included 886 twin pairs, aged 11-17 years, derived from a population-based twin study. The second sample was derived from a longitudinal community study and included 282 parents and their children, aged 11-14 years. Questionnaires were used to assess ADHD symptoms and hostility in the mother-child and father-child relationship. Bivariate genetic analysis was used to test the contribution of genetic and environmental factors to the association between parent-child hostility and ADHD symptoms in the twin sample. Cross-lagged and reciprocal effects models were used to test for a bidirectional relationship between parent-child hostility and ADHD symptoms over time in the longitudinal study.
  
  
  RESULTS
  For boys, both genetic and environmental factors contributed to the link between mother-son hostility and ADHD symptoms, but genetic factors alone explained the association between father-son hostility and ADHD symptoms. For girls, the association between ADHD symptoms and mother-daughter hostility as well as father-child hostility was attributed to genetic factors alone. The longitudinal study provided evidence of boys' ADHD symptoms impacting upon mother-son hostility both within and across time. There were no effects in the opposite direction.
  
  
  CONCLUSIONS
  A causal hypothesis of family relations influencing ADHD symptoms was not supported. Boys' ADHD symptoms appear to have an environmentally mediated impact upon mother-son hostility.
authors.affiliation: Cardiff University, UK. Liffordkj1@cf.ac.uk
authors.forename: Kate J
authors.initials: KJ
authors.lastname: Lifford
authors.forename: Gordon T
authors.initials: GT
authors.lastname: Harold
authors.forename: Anita
authors.initials: A
authors.lastname: Thapar
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology*; D002648:Child; D004777:Environment; D005260:Female; D005500:Follow-Up Studies; D006791:Hostility; D006801:Humans; D008297:Male; D010287:Parent-Child Relations; D012737:Sex Factors; D011795:Surveys and Questionnaires