Creators of change or people who have problems with authority are increasingly likely to be medicated and face a lifetime of addiction, Professor Cohen, of Florida State International University, told an Edinburgh University conference on the rise of ADHD.
He issued "a huge stern warning" not to follow the United States - which was 10 years ahead - on a path of drugs dependency. But Professor Cohen doubted whether Britain could hold the tide in favour of more rounded and diverse social approaches to a condition which has been officially recognised for just three years but whose incidence has increased rapidly in the past eight.
Professor Cohen said it had become a way of life for children to attract the ADHD label. In the United States, it is treated by 15 different drugs, not mainly Ritalin as in the UK. Between three million and seven million US children were "drugged". In parts of Virginia, up to 17 per cent of boys, or one in six of 8-12s, were on stimulant medication to contain their behaviour in school.
Scottish parents, he warned, should be more sceptical about the advice of clinical psychologists and other experts. "Fifteen years from now we will look back and, like every other therapeutic fad, say it just didn't deliver and created new serious problems," Professor Cohen said.
Graham Bryce, of Yorkhill NHS Trust in Glasgow, one of Scotland's most prominent commentators on child health, said we were "four to five years into the biggest dilemma or crisis in Scottish mental health we have seen".
A major report on child and adolescent mental health published within the next few weeks will highlight problems with ADHD.
Dr Bryce said that based on two-year-old figures, 18 per 1,000 children were on Ritalin, a fourfold increase over four years. It was untrue that those who prescribed drugs were unconcerned. They saw it as a contentious issue and were anxious about overuse.
Bryan Kirkaldy, a senior education official in Fife and former principal psychologist, said 534 - or 1 per cent - of Fife children were diagnosed with the condition, of whom 420 were on prescribed medication, normally Ritalin. Another 200 are on a six-month waiting list to see a clinical psychologist.
Fife has the highest prescribing record in Scotland and every class could soon have one or two children on Ritalin.
Mr Kirkaldy said that 59 of the Fife cohort had had no assessment in school before their diagnosis and 49 were considered by teachers not to be overactive. Many teachers were concerned about administering Ritalin during school hours when they did not consider the children to be overactive.