Attention Deficit Disorder is caused by a chemical imbalance in the brain. There appears to be a deficiency in the brains ability to produce or use certain chemicals called transmitter substances or neurotransmitters. The theory is that a shortage of certain neurotransmitters results in the brain being under-stimulated, therefore it's deficient in regulating its own activities such as attention.
Attention Deficit Disorder is characterized by a number of common symptoms. The symptoms are short attention span or distractibility, impulsiveness, and hyperactive. This results in social problems and disorganization. As ADD kids get older they feel stupid and are often accused of being lazy. Kids with Attention Deficit Disorder tend to daydream allot more than others.
People with ADD are easily distracted and have limited attention spans. They can sit for a while and pay attention if the topic is interesting to them. People with Attention Deficit Disorder usually do this while watching TV, playing Nintendo, and at sporting events.
Many ADD children will tell you how annoying it is when someone around them is talking.
People with ADD are impulsive meaning to act without thinking. In one case a five-year old with ADD almost drowned when he went to a pool with his father. He saw people jumping into the pool and thought it would be fun. He jumped right in without remembering that he can't swim. He was pulled from the bottom of the pool several minutes later.
Hyperactivity is a real problem for people with ADD especially in children. Parents will usually describe them as always on the go. ADD girls tend to be less hyperactive than ADD boys are. The hyperactivity usually fades by adolescence. This doesn't mean all the symptoms are gone though. There are only a limited number of ADD children who can't sit still...