A 2025 study in Psychological Science looked at how shared genetic and environmental factors might affect the chance of having attention-deficit/hyperactivity disorder (ADHD), dyslexia (trouble with reading) and dyscalculia (trouble with math) at the same time. The scientists used data from the Netherlands Twin Register involving approximately 19,000 twins and 2,000 siblings, analyzing teacher-provided information and standardized test scores at ages 7 and 10.

The study showed that 77.3 percent of the children had only one of these specific conditions, but the risk for multiple conditions was two to three times more likely because the three conditions share similar genetic predispositions, not because one disorder causes another. The researchers noted that although these neurodevelopmental conditions are deeply connected, each condition should be assessed and treated separately because treating one condition is unlikely to automatically improve the others.