Notes may be redistributed only if the above commentary is included. Barkley is working on a new theory to explain the psychobiology beneath the spectrum of symptoms usually considered to be part of the ADD syndrome. All of these symptoms are observed in 'normal' people at one time or another - they differ in people with ADHD by reason of their presence since childhood, their persistence beyond childhood, and their severity. Barkley says that ADD has more to do with lost interest than with an inability to concentrate. Boys are affected at three times the rate.
ADD crosses all social barriers, and is present is all ethnic groups and social classes.
Some think ADD arises from a faulty 'filtering' mechanism, but this is not the case - it has to do with motivation. ADD is not an attention disorder, but a disorder of impulse control. ADD children do things other kids think of, but don't actually do. The urge to act is not being inhibited. The first response is the immediate response.