What Is the Genetic Link With ADHD?
There is increasing evidence from medical studies that genetic factors play a role in ADHD. Jacquelyn Gillis and her team, then at the University of Colorado, reported in 1992 that the risk of ADHD in a child whose identical twin has the disorder is between 11 and 18 times greater than that of a non-twin sibling of a child with ADHD. She showed that between 55 and 92 percent of the identical twins of children with ADHD eventually develop the condition. A large study of twins in Norway, involving 526 identical twins (who inherit exactly the same genes) and 389 fraternal twins (who are no more alike genetically than siblings born years apart) found that ADHD had nearly an 80 percent chance of being inherited. They concluded that up to 80 percent of the differences in attention, hyperactivity and impulsivity between people with ADHD and those without the disorder can be explained by genetic factors. In addition, scientists are telling us that there are genetic mechanisms that regulate hyp
