Is ADHD hereditary?

ADHD is one of the neurodevelopmental conditions with the strongest genetic component: heritability is estimated between 70-80%, meaning most of the variation in ADHD risk is explained by genetic factors.

In practice: if one parent has ADHD, their child has roughly a 40-60% chance of also having it. If both parents have it, the risk is even higher. Having a sibling with ADHD also significantly increases the risk.

There is no single "ADHD gene" — multiple genes, each with a small effect, contribute to the risk. Beyond genetics, environmental factors also play a role (extreme prematurity, lead exposure, prenatal infections), but they account for a much smaller share of the risk.

This also means that when a child is diagnosed with ADHD, one or both parents often recognize the same patterns in themselves — and frequently arrive at their own diagnosis through their child's.