ADHD in Children
Visual Abstract
The genetic association between ADHD symptoms and reading difficulties: the role of inattentiveness and IQ
Genetics of ADHD, IQ, and Reading
Yannis Paloyelis , Fruhling Rijsdijk, Alexis C Wood, Philip Asherson, Jonna Kuntsi
Summarized by:
April 23, 2023
study source
J Abnorm Child Psychol.
Nov 2010
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What they studied
This study wanted to examine the genetics of ADHD, IQ, and reading. Researchers wanted to see whether the link between reading and ADHD is caused by genetics, intelligence, or upbringing.
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What they found
ADHD and reading ability share many genetic factors, mostly independent of intelligence. Upbringing also plays a role.
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What this means
ADHD is closely linked with reading ability, but this link is not driven by intelligence for the most part. Many of the genes behind ADHD also may cause reading difficulties.
The genetic association between ADHD symptoms and reading difficulties: the role of inattentiveness and IQ
Objectives
By definition, difficulties with attention and hyperactivity define ADHD.
ADHD has also been linked to challenges in school, particularly with reading.
This study wanted to analyze the link between ADHD and reading difficulties. In particular, the researchers wanted to see whether genetics play a role in the link. Do the same genes that drive ADHD also drive difficulties in reading?
Study Quote
Previous studies have documented the primarily genetic aetiology for the stronger phenotypic covariance between reading disability and ADHD inattention symptoms, compared to hyperactivity-impulsivity symptoms. In this study, we examined to what extent this covariation could be attributed...
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Methods
Researchers conducted the study on data from 1312 twins. They collected information on ADHD symptoms and reading ability and estimated the effects of genetics.
Study Quote
We used multivariate structural equation modeling on IQ, parent and teacher ADHD ratings and parent ratings on reading difficulties from a general population sample of 1312 twins aged 7.9-10.9 years.
Results
Overall, 45% of the link between ADHD and reading difficulties was driven by genetic factors. This means that ADHD and reading ability likely share many of the same genes
21% was driven by the environment, which refers to a child’s home and upbringing.
Only 11% was attributable to genes linked with IQ.
The effect of a child’s upbringing was a surprising finding. This result suggests how a child is raised and educated affects ADHD and reading ability.
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Another novel finding in this study was that child- specific environment factors (including possible error) were uniquely shared between reading difficulties and inattention symptoms, making a significant contribution (21%) to their covariance.
Study Quote
The covariance between reading difficulties and ADHD inattention symptoms was largely driven by genetic (45%) and child-specific environment (21%) factors not shared with IQ and hyperactivity-impulsivity; only 11% of the covariance was due to genetic effects common with IQ. Aetiological ...
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Conclusions
These results confirm the strong link between ADHD and reading ability.
The data shows that much of this link is driven by genetics. The genes that cause ADHD also cause difficulties with reading.
However, for the most part, this is independent of IQ.
These results suggest that when a child with ADHD has difficulty with reading, they aren’t struggling intellectually. Rather, challenges with attention and focus are most likely getting in the way.
Study Quote
The current study, using a general population sample, extends previous findings by showing, first, that the shared genetic variability between reading difficulties and ADHD inattention symptoms is largely independent from genes contributing to general cognitive ability and, second, that ...
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