Siblings born to a family after children with autism spectrum disorder or ADHD were more likely to be diagnosed with the same disorder as well as the other disorder, study findings reported.

Although sibling recurrence risk is a common way to measure shared genetic contributions, multiple confounders can obscure recurrence risk estimates for familial disorders, Meghan Miller, PhD, from the department of psychiatry and behavioral sciences, University of California Davis Health System, and colleagues explained in their study, published in JAMA Psychiatry.