If you have ADHD, chances are higher that your siblings do, too. Estimates differ as to how strong the connection is, but the arrows point in the same direction: genetics helps determine someone’s risk for ADHD. Beyond that, we still have myriad questions and not many answers—which genes play a role? And how do those genes affect someone’s ability to focus or sit still?
Some conditions, like sickle-cell anemia, rest entirely on a single small genetic change; but others, like schizophrenia, rest on a dizzying array of genetic differences, all seemingly linked to an infinitesimally tiny increase in risk.
ADHD is much closer to schizophrenia. A paper published in Nature Genetics this week looked at genetic data from more than 50,000 people, finding 12 different regions of DNA that seemed to play a role in increasing ADHD risk.