Understanding ADHD
What causes ADHD?

Research has demonstrated that ADHD has a very strong neurobiological
basis. Although precise causes have not yet been identified, there is
little question that heredity makes the largest contribution to the
expression of the disorder in the population.
In instances where heredity does not seem to be a factor,
difficulties during pregnancy, prenatal exposure to alcohol and tobacco,
premature delivery, significantly low birth weight, excessively high
body lead levels, and postnatal injury to the prefrontal regions of the
brain have all been found to contribute to the risk for ADHD to varying
degrees.
HAVE QUESTIONS? We can help.
Learn more about the disorder on the CHADD website and at CHADD’s
National Resource Center on ADHD. You
may also contact us online
or by phone (800-233-4050) and a health information
specialist will provide a personalized response.