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.

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More on Causes of ADHD for CHADD Members

Interest Deficit - We found decreased activity of the reward system in individuals with AD/HD, and that translates into a decreased sensitivity to being able to be engaged by activities that are not inherently rewarding or reinforcing.

Researchers on ADHD Research - There is more than a hundred years of research documenting the existence of AD/HD and offering answers as to the best ways to treat the neurobiological disorder.