Conflicts of interest statement: No conflicts declared.
Evidence for shared genetic risk between ADHD symptoms and reduced mathematics ability: a twin study
Version of Record online: 3 JUN 2013
© 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.
Journal of Child Psychology and Psychiatry
Volume 55, Issue 1, pages 39–48, January 2014
How to Cite
Greven, C. U., Kovas, Y., Willcutt, E. G., Petrill, S. A. and Plomin, R. (2014), Evidence for shared genetic risk between ADHD symptoms and reduced mathematics ability: a twin study. Journal of Child Psychology and Psychiatry, 55: 39–48. doi: 10.1111/jcpp.12090
There is no gold-standard, universally applied definition of mathematics disability, and the literature is additionally complicated by the use of inconsistent labels (e.g., mathematics difficulties/underachievement/disability/disorder, developmental dyscalculia, reduced mathematics ability/skill), some of which differ conceptually. For the literature reviewed in this paper, we make no differentiation between these labels and concepts. However, for the data shown in this paper, we consider the term ‘mathematics ability’ to refer to a normally distributed complex trait that ranges from low (disability) to high (ability).
- Issue online: 14 DEC 2013
- Version of Record online: 3 JUN 2013
- Manuscript Accepted: 15 APR 2013
- U.K. Medical Research Council. Grant Numbers: G0901245, G0500079
- U.S. National Institute of Child Health and Human Development . Grant Numbers: HD49861, HD44454, HD46167, HD059215
- Government of the Russian Federation. Grant Number: 11.G34.31.003
- ADHD ;
- twin study;
- general cognitive ability
Attention-deficit/hyperactivity disorder (ADHD) symptoms and mathematics ability are associated, but little is known about the genetic and environmental influences underlying this association.
Data came from more than 6,000 twelve-year-old twin pairs from the UK population-representative Twins Early Development Study. Parents rated each twin's behaviour using a DSM-IV-based 18-item questionnaire of inattentive and hyperactive–impulsive ADHD symptoms. Mathematics tests based on the UK National Curriculum were completed by each twin. The twins also completed standardised tests of reading and general cognitive ability. Multivariate twin model fitting was applied.
Inattentive and hyperactive–impulsive ADHD symptoms were highly heritable (67% and 73% respectively). Mathematics ability was moderately heritable (46%). Mathematics ability and inattentiveness showed a significantly greater phenotypic correlation (rp = −.26) and genetic correlation (rA = −.41) than mathematics ability and hyperactivity–impulsivity (rp = −.18; rA = −.22). The genetic correlation between inattentiveness and mathematics ability was largely independent from hyperactivity-impulsivity, and was only partially accounted for by genetic influences related to reading and general cognitive ability.
Results revealed the novel finding that mathematics ability shows significantly stronger phenotypic and genetic associations with inattentiveness than with hyperactivity–impulsivity. Genetic associations between inattentiveness and mathematics ability could only partially be accounted for by hyperactivity–impulsivity, reading and general cognitive ability. Results suggest that mathematics ability is associated with ADHD symptoms largely because it shares genetic risk factors with inattentiveness, and provide further evidence for considering inattentiveness and hyperactivity–impulsivity separately. DNA markers for ADHD symptoms (especially inattentiveness) may also be candidate risk factors for mathematics ability and vice versa.