ADHD is a neurological disorder that affects a person's ability to control their behavior and pay attention to tasks.
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.
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.
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.
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.
Last Reviewed: November 15, 2012