title: Developmental twin study of attention problems: high heritabilities throughout development.
abstract: BACKGROUND
  The genetic and environmental link between attention-deficit/hyperactivity disorder in childhood and the adult manifestation of the disorder is poorly understood because of a lack of longitudinal studies with cross-informant data.
  
  
  OBJECTIVE
  To explore the relative contribution of genetic and environmental influences on symptoms of attention problems from childhood to early adulthood.
  
  
  METHODS
  Analysis was conducted using longitudinal structural equation modeling with multiple informants.
  
  
  METHODS
  The Swedish Twin Study of Child and Adolescent Development.
  
  
  METHODS
  One thousand four hundred eighty twin pairs were prospectively followed up from childhood to young adulthood.
  
  
  METHODS
  Symptoms were obtained using parent and self-ratings of the Attention Problems Scale at ages 8 to 9, 13 to 14, 16 to 17, and 19 to 20 years.
  
  
  RESULTS
  The best-fitting model revealed high heritability of attention problems as indexed by parent and self-ratings from childhood to early adulthood (h² = 0.77-0.82). Genetic effects operating at age 8 to 9 years continued, explaining 41%, 34%, and 24% of the total variance at ages 13 to 14, 16 to 17, and 19 to 20 years. Moreover, new sets of genetic risk factors emerged at ages 13 to 14, 16 to 17, and 19 to 20 years.
  
  
  CONCLUSIONS
  The shared view of self- and informant-rated attention problems is highly heritable in childhood, adolescence, and early adulthood, suggesting that the previous reports of low heritability for attention-deficit/hyperactivity disorder in adults are best explained by rater effects. Both genetic stability and genetic innovation were present throughout this developmental stage, suggesting that attention problems are a developmentally complex phenotype characterized by both continuity and change across the life span.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. zheng.chang@ki.se
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chang
authors.forename: Paul
authors.initials: P
authors.lastname: Lichtenstein
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Asherson
authors.forename: Henrik
authors.initials: H
authors.lastname: Larsson
mesh_terms: D000293:Adolescent; D041923:Adolescent Development; D000367:Age Factors; D001289:Attention Deficit Disorder with Hyperactivity / Q000209:etiology / Q000235:genetics; D002648:Child; D002657:Child Development; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008957:Models, Genetic; D010641:Phenotype; D012737:Sex Factors; D014427:Twins / Q000235:genetics* / Q000523:psychology; D014429:Twins, Dizygotic / Q000235:genetics / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics / Q000523:psychology; D055815:Young Adult