The role of genetics in the development of ADHD has only recently been discovered. However, ADHD is now among the most recognized genetics-based disorders in psychiatry.

Between 10 and 35 percent of children with ADHD have a very close relative with ADHD, and nearly one half of parents who had ADHD as a child also have a child with the disorder. Studies done in families of children with ADHD show that relatives of affected children are at high risk themselves for having ADHD and other psychiatric disorders, as well as learning disabilities.

Additional research from studies with twins done over the past decade shows that, when ADHD is present in one twin, it is significantly more likely to be present in an identical twin than in a fraternal twin.

An individual's gender has been another point of interest in the field of Adult ADD research. Scientists have recently focused closely on the differences in the effect of Adult ADD on women.