Although limited attention span is characteristic of people suffering from severe debilitation, it may also occur under other circumstances. It results in inability to concentrate for any length of time, distractedness, irritation, restlessness and impatience. It may be associated with chronic alcoholism, drug abuse and delinquency. Distractedness is especially characteristic of children who normally grow out of it.
In 1989 it was estimated that in the USA from 3 to 10% of children (approximately 70% boys) had attention deficit problems. Over 30% of school children continue to have such problems as adults. From 2 to 5% of American adults (namely 6 million) suffer in this way. Nearly 50% of the children who do suffer from it also have specific learning disabilities characteristic of dyslexia. Nearly 30% are diagnosed as anti-social or as having a conduct disorder.