A few weeks ago I visited High Society, an exhibition on the history of psychotropic drugs and their legal and illegal use in societies across the world. It was an eye-opening experience. For example, the opium trade had been largely unknown to me, and I had not realised that the opium plantations in India were one of the Empire's most profitable assets. The questions of morals and ethics raised by the exhibition are highly relevant to the present day. With my metaphorical tongue tucked firmly into my cheek, I considered whether this ought to be part of the national curriculum.

So it was with a new interest that I read that 650,000 children in England between eight and 13 were prescribed Ritalin or similar drugs during 2010. This is a seven-fold increase since 1997 and represents almost 20 per cent of pupils in these age groups. To bring this closer to home, in a class of 25 pupils in Key Stages 2 or 3, a teacher may expect there to be five children who have been medicated with a psychotropic drug, largely prescribed to deal with ADHD.

This raises several questions. Do the teachers know which children have been medicated in this way? How are the children identified? What research is being done on effectiveness? With such a large sample, the evidence of improved behaviour should be easy to find; but there has not, I believe, been a significant trend of improving behaviour.

So it was with a sense of some relief that I discover that the government is acting against what is called the Prozac generation, and is proposing to reduce substantially the prescribing of such drugs. No doubt there is a saving to be made here - Ritalin costs upwards of £200 per pupil a year so the total annual cost is around £130m - and that will not have escaped the Department of Health. But any move to prescribe on evidence rather than fashion will get my vote.

John Freeman CBE is a former director of children's services and is now a freelance consultant. Read his blog at cypnow.co.uk/freemansthinking