Oosterlaan, Logan and Sergeant referred to this condition as 'Response Inhibition' in their article, in Cambridge Journals. Earlier it was presumed that it was only a boy's disorder and never affected girls. Recent information has proved otherwise and now the actual ratio of boys: girls is 3:1. Till recently, hyperactive and impulsive behavior had always been considered as part of childhood and not exactly a problem. Also boys are given more attention, because their behavior is more aggressive and caught attention and hence, were treated accordingly.
These are connected with poorer performance, less systematic behavior, loss of working memory, lack of focused attention, irritability, restlessness, inability to carry out specific instructions, and lack of concentration in any activity without being distracted.
It is considered to be difficult to diagnose the inattentive kind, as behavior does not show it. According to unconfirmed data 4% to 5% of United States citizens have AD/HD related problems. It persists throughout a person's lifetime. Approximately one-half to two-thirds of children do not get completely treated and will continue have the same behavioral problems even as adults that will create tension for them on the job, within the family and in social relationships.
It is supposed to be caused mainly by biological factors, said to be the 'influence in neurotransmitter activity' in the brain. Research leads us to believe that this has a definite genetic basis. Research conducted by NIMH using a positron emission tomography scanner to map out the working procedure in the brain has resulted in showing a certain unbroken connection between the ability to hold sustained attention and the activity level in the brain. In this research, the level of glucose used by various areas of brain which could be in control of impulses and quick decisions was carefully measured. Those areas in an affected person showed decreased activity, as a result of consumed lesser level of glucose.
"In people with AD/HD, the brain areas that control attention used less glucose, indicating that they were less active. It appears from this research that a lower level of activity in some parts of the brain may cause inattention and other AD/HD symptoms." http://www.add.org/articles/factsheet.html
Earlier diagnosis would solve the problem being carried forward into adulthood, but sometimes, this would not happen. This problem could be excessive, long term and exasperating to the person and people around him. Adult AD/HD is considered to be difficult only if it has created problems either at work place or in the social life of individual. If a certain handicap is felt in these areas, perhaps it should be treated clinically. Because the nature and severity of the problem could vary from person to person, it is not very easy to come to a conclusive diagnosis without any stray doubt. Sometimes, it is not rare to come across a family history of the problem.
"Adult anxiety disorders have been shown to be familial. The familial patterns are likely due to a combination of genetic and environmental factors, Garfinkel et al