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   ADHD stands for attention deficit hyperactivity disorder. It is a common disorder that often results in learning difficulties. People with this disorder act impulsively and are easily distracted. They may also exhibit hyperactive behavior. While some specialists consider ADHD a behavioral disorder, others call it a cognitive disorder.

   The cause of ADHD is unknown. However, brain scans indicate that it may be caused by abnormal size, function, and form of the brain’s frontal lobe. There may also be an imbalance of chemicals in the brain. ADHD is believed to be inherited in most cases, but it is also prevalent in premature babies and children who have experienced head injuries.  

   The disorder ADD (attention deficit disorder) was renamed ADHD to account for the “hyperactivity” that is often one of the major symptoms found in people with the disorder. The disability can exist without the presence of hyperactivity, in which case it is referred to as a subset of ADHD called ADD. Both terms are often used to describe the same disorder.

    Children can exhibit ADHD symptoms at a very young age, and are often diagnosed before the age of seven. On the other hand, some adults do not realize they have this disorder until their own children are diagnosed with it. Some symptoms, such as hyperactivity, may be less severe as a child ages and learns coping mechanisms. 

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