A study published in Psychological Science suggests that shared genetic risk helps explain why ADHD, dyslexia and dyscalculia often appear in the same child. Using data from thousands of twins in the Netherlands, researchers found that the genetic factors linked to ADHD symptoms overlap with genetic factors tied to reading, spelling and math performance. That matters for families and educators because it supports a fuller view of learning struggles that can show up together in everyday school life. The research paper is available via this DOI.
The work was led by researchers based at the University of Amsterdam and Vrije Universiteit Amsterdam, using the Netherlands Twin Register. Their core message is simple: when attention and learning difficulties cluster, genetics can be one reason the cluster happens.
Why ADHD, Reading Problems And Math Problems Often Show Up Together
Teachers and parents have noticed a pattern for years. A child who struggles to sit still and focus may also struggle with reading or math. Clinicians and researchers call this “co-occurrence,” and it shows up often enough that it has become a big question in developmental psychology.
One reason this pattern matters is that schools usually sort support into separate boxes. There are reading supports, math supports and behavior supports. Real kids do not always fit those boxes and many families end up juggling several kinds of help at once.
In this study, the researchers focused on three common challenges: ADHD, dyslexia and dyscalculia. ADHD involves ongoing difficulties with attention, impulsivity and activity level that affect daily life. Dyslexia is linked to difficulty with accurate and fluent reading, plus spelling challenges. Dyscalculia involves persistent difficulty understanding numbers and learning math skills.
Some explanations for co-occurrence focus on day-to-day pathways in school. For example, a child who finds reading exhausting may tune out in class. A child with strong impulsivity may miss practice time that builds reading and math skill. These pathways can happen in real classrooms, even when teachers are doing their best.
This study asked a deeper question about roots. Are these conditions connected because one tends to set the stage for another over time, or because they share underlying influences from the start? The findings pointed strongly toward shared influences, with genetics playing a major role.
Twin Data Let Researchers Separate Genetic Links From School And Home Effects
To untangle genes and environment, the team used data from the Netherlands Twin Register. Twin studies help because identical twins share almost all of their genes, while fraternal twins share about half on average. Both types of twins usually share many parts of home and school life.
The sample was large, which strengthens confidence in the patterns. The researchers analyzed data from 19,125 twins from 10,365 families. The children were followed at two points in childhood, around age 7 and around age 10.
At school, teachers reported on children’s attention and behavior using questionnaires. These teacher ratings focused on behaviors that match ADHD symptoms in the classroom. The measures were designed to stay separate from academic performance, so the behavior ratings did not blend into grades or test results.
Academic skills were measured with national school tests from the Dutch Pupil Monitoring System. This provided standardized test scores that were comparable across students. The tests covered reading fluency, spelling and mathematics.
Because the children were assessed at two ages, the researchers could also look at stability across time. Many kids change as they grow, yet some difficulties persist. The two time points helped the team examine how the links among attention and learning looked in early and later primary school.
Genetic Overlap Connected ADHD With Reading, Spelling And Math Scores
The main result was that the same genetic influences contributed to multiple outcomes. Genetic factors related to ADHD symptoms overlapped with genetic factors related to reading, spelling and math. In plain terms, some children inherit a mix of genetic tendencies that makes both attention control and academic skill-building harder.
The research team used statistical models designed for twin data to estimate how much of the overlap came from genetics and how much came from shared environments. Their analyses supported a strong genetic contribution to the connections among these traits. The results fit with a broader body of work in behavioral genetics showing substantial heritability for many learning and attention differences.
Reading was assessed using reading fluency, which captures how quickly and accurately a child can read words. Spelling was tested with dictation tasks, where students write words they hear. Mathematics included a range of topics, such as number operations and problem-solving across different domains.
Across these measures, the pattern stayed consistent. Children with higher ADHD symptom levels tended to show lower academic scores. The key takeaway was about why the pattern exists: the study’s evidence supported genetic overlap as a major shared driver of these differences.
Quick takeaway: The study supports a “shared roots” explanation, where overlapping genetic influences contribute to both attention symptoms and learning performance.
Co-Occurring Difficulties Were Common In The School-Age Sample
Alongside the genetic modeling, the study also described how often these challenges appeared together. The researchers found that 37% of children who met criteria for ADHD also showed signs of dyslexia or dyscalculia. That number helps put the everyday experience of co-occurrence into perspective.
When the researchers compared groups, ADHD was linked to higher odds of learning difficulties. Children with ADHD were about 2.7 times more likely to have dyslexia and about 2.1 times more likely to have dyscalculia than children without ADHD. The pattern also worked in the other direction, with children showing dyslexia or dyscalculia more likely to show ADHD symptoms.
These overlaps can be easy to miss in a busy school setting. A child might stand out for behavior first, while reading difficulty stays hidden behind effort and coping strategies. Another child might get flagged for reading or math struggles, while attention problems show up as daydreaming that looks quiet and polite.
What The Findings Suggest For Screening And Support In Schools
The results support a practical idea: when one difficulty appears, it can be useful to check for others. In a school context, that can mean looking at reading, spelling and math when a child shows persistent attention and impulse control challenges. It can also mean paying attention to focus and self-control when a child shows strong academic struggles.
From a lifestyle angle, this matters for family stress too. When kids have a mix of challenges, daily routines can feel intense. Homework can stretch longer than expected. Mornings can include conflict about getting started. Families often interpret these patterns as motivation problems and that interpretation can add emotional pressure.
Schools often provide help through separate services. This study supports a more connected approach, where educators see learning difficulties and attention differences as traits that can share underlying influences. A team approach can also help teachers communicate more clearly, since reading teachers, math teachers and classroom teachers may each be seeing a different piece of the same child.
It also supports realistic expectations. The study authors highlighted that many individual differences in these skills are influenced by genetics. They also emphasized that education remains crucial, since children learn these skills through teaching and practice. In other words, genetic influence and classroom support can both be part of the same story.
Helpful lens for parents and teachers: A child’s struggles can reflect a broad learning and attention profile. That profile can guide support decisions and reduce blame-based thinking.
At the same time, co-occurrence was far from guaranteed. Many children with one condition did not show another. That point matters because it encourages individualized support, even when two children share the same label.
Study Limits And What Researchers Want To Test Next
As with any study, there are boundaries around what the results can tell us. The data came from children in the Netherlands, within one national school system. Patterns may look different in countries with different education structures, languages and testing practices.
The study relied on teacher questionnaires for ADHD symptoms. Teachers observe children in a setting that demands attention and self-control, which is a strength. Still, teacher ratings can differ from parent ratings and they may miss symptoms that show up mainly at home.
The academic measures were standardized and objective, which supports strong measurement. Even so, test performance reflects more than skill alone. Sleep, stress, classroom fit and confidence can shape how a child performs on a given day.
Looking ahead, the authors described interest in understanding how genetic and environmental factors work together across development. Future work can examine which classroom factors help the most for children with higher genetic risk and which supports best match different combinations of attention and learning profiles.