title: A genetic study on attention problems and academic skills: results of a longitudinal study in twins.
abstract: OBJECTIVE
  Several studies reported a negative association between ADHD symptoms and academic achievement. We investigated the etiology of the association between Attention Problems (AP, one of the core symptoms in ADHD) in early childhood and four academic skills across childhood in a genetically informative design.
  
  
  METHODS
  Academic skills (mathematics, spelling, reading and comprehension) were measured with standardized tests performed at school in grade 2, 4, and 6. AP were measured with mother ratings of the Devereux Child Behavior Rating Scale at age 5 and the Child Behavior Checklist at age 7. Subjects were 767 Dutch twins from 445 families.
  
  
  RESULTS
  AP were negatively associated with most academic skills in each grade, and this association was stable over time. Correlations of AP with mathematics and comprehension were around -0.20, and with spelling around -0.15. Correlations with reading were not significant. A significant genetic correlation (-0.40) between AP and mathematics across time indicated that shared genes play a role for these measures. The genetic correlations of AP with spelling and comprehension (both -0.28, p= 0.09) were non-significant.
  
  
  CONCLUSIONS
  More complex academic skills, requiring higher cognitive processes, like mathematics and comprehension, are especially negatively associated with attention problems. The association between AP and mathematics is partly due to shared genes, while the association with comprehension, and spelling was driven by unique environmental factors.
authors.affiliation: Department of Biological Psychology, VU University Amsterdam, The Netherlands.
authors.forename: Tinca J C
authors.initials: TJ
authors.lastname: Polderman
authors.forename: Anja C
authors.initials: AC
authors.lastname: Huizink
authors.forename: Frank C
authors.initials: FC
authors.lastname: Verhulst
authors.forename: Catherina E M
authors.initials: CE
authors.lastname: van Beijsterveldt
authors.forename: Dorret I
authors.initials: DI
authors.lastname: Boomsma
authors.forename: Meike
authors.initials: M
authors.lastname: Bartels