ADHD Study: General Information

National Human Genome Research Institute

National Institutes of Health
U.S. Department of Health and Human Services


Banner image of the ADHD Genetic Research Study at NIH with photographs of children's faces

The ADHD Genetic Research Study at the National Institutes of Health and The National Human Genome Research Institute

General Information About ADHD

What is Attention Deficit Hyperactivity Disorder (ADHD)?

ADHD is a neurological disorder that affects a person's ability to control their behavior and pay attention to tasks.

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What causes ADHD?

ADHD has many causes. Among these causes are: 1) familial: ADHD often runs in families; 2) abnormal brain development; or 3) brain injuries occuring before, during or after birth.

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Why is ADHD considered a neurological condition?

Brain images of children with ADHD may show differences compared to children without ADHD. For example, in some children with ADHD certain parts of the brain are smaller or less active than the brains of children without ADHD. These changes may be linked to specific brain chemicals that are needed for tasks such as sustaining attention and regulating activity levels.

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What are some of the other conditions that are common in children with ADHD?

Some children with ADHD may also have learning disabilities, behavioral disorders or disorders of mood such as depression or anxiety. Problems with planning, memory, schoolwork, motor skills, social skills, control of emotions, and response to discipline are common. Sleep problems can also be more frequent.

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What is the risk of having ADHD if other family members have ADHD?

Children who have ADHD usually have at least one close biological (blood) relative who also has ADHD. At least one-third of all fathers who had ADHD in their youth have children with ADHD. Research has shown that ADHD can have a genetic basis, which means that it is likely that a person diagnosed with ADHD has a close relative with similar symptoms.

Please see our listing of book resources and on-line ADHD resources for more information on ADHD.

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Last Reviewed: November 15, 2015