ADHD, Dyslexia, and Dyscalculia Share Genetic Roots

Researchers have found that ADHD, dyslexia (difficulty with reading), and dyscalculia (difficulty with math) often occur together because they share some of the same genetic influences.

In a large 2025 study, scientists analyzed data from 19,125 twins in the Netherlands, assessing them at ages 7 and 10. Teachers reported ADHD symptoms, and the children completed standardized tests measuring reading, spelling, and math skills. By comparing identical twins (who share all their genes) with fraternal twins (who share about half), researchers could estimate how much genetics contributes to these conditions.

The study found that children with one of these conditions were two to three times more likely to have another. However, the overlap was smaller than previously believed—only 23% of children with one condition had at least one additional condition.

When researchers examined the relationships between the traits, they discovered that most overlaps were explained by shared genetic factors, rather than one condition causing another. The only clear causal link was between reading and spelling, where reading ability influenced spelling performance.

These findings suggest that ADHD, dyslexia, and dyscalculia often appear together because they arise from similar underlying genetic influences, not because one disorder leads to another. As a result, treating one condition is unlikely to automatically improve the others.

The researchers say this means each condition should be assessed and treated individually, even when a person has more than one. Understanding the shared genetic roots may help scientists develop better support and interventions for people experiencing these learning and attention challenges.