Is attention deficit/hyperactivity disorder hereditary? My sister-in-law has it, so will our kids have a greater chance of having it?
Your sister-in-law’s children may develop attention deficit/hyperactivity disorder, but that doesn’t make your kids any more prone to it – unless you also have a family history of ADHD. We still have a lot to learn about ADHD and the role of heredity. However, research suggests and experts agree that most cases of ADHD can be explained by genetics.
In a large study of families of ADHD children, it was found that 25 percent of the first-degree relatives of these children -that is, daughters, sons, brothers and sisters, moms and dads – also had ADHD. This is a big leap from the 3 to 5 percent occurrence of ADHD in the general population. In twin studies, scientists also discovered that if one twin is diagnosed with ADHD, there is a 79 percent chance that an identical twin will have ADHD and a 32 percent chance that a fraternal twin will have it.
We’ve also seen evidence that ADHD may sometimes be caused by complications of pregnancy or labor and delivery, exposure to toxins such as lead, and possibly other environmental or family circumstances.