What causes AD/HD?

Research has demonstrated that AD/HD 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 AD/HD to varying degrees.

Have questions? We can help.  Learn more about the disorder at CHADD’s National Resource Center on AD/HD. You may also contact us online or by phone (800-233-4050) and a health information specialist will provide a personalized response.