The amount the National Health Service shells out on therapies to treat attention-deficit hyperactivity disorder in children and adolescents could rocket to £101 million by 2012, according to research published online in the journal Child and Adolescent Psychiatry and Mental Health.

The findings are based on a model created by Michael Schlander of the University of Heidelberg, which used demographic and epidemiological data, spending patterns, novel therapies nearing launch and other variable factors to forecast a range of potential costs to the NHS and health insurers in Germany.

A BBC Panorama programme aired on Monday night claimed that the National Health Service currently spends £28 million on ADHD drugs, but Schlander has predicted that the bill will swell to anywhere between £49 million and £101 million by 2012, and that all the scenarios plugged into the model “strongly suggest that the trend of rising drug expenditures for ADHD may not abate in the near future”.

Publication of the research is certainly timely, as questions over the actual benefit of ADHD therapy are being raised in the wake of recently-unveiled study findings that found no advantage of drug therapy over behavioural therapy after a three year follow-up.

The first US-based Multimodal Treatment Study found that treatment with stimulant drugs such as Novartis' Ritalin (methylphenidate) alone or in combination with behavioural therapy produced better outcomes after one year than just behavioural therapy or usual community care alone. But results of a three-year follow up seem to paint an entirely different picture that these medicines don’t help in the long run.

Further evaluation
However, findings of the study are by no means clear cut and still need to undergo a full evaluation to discover the reasons behind this observation, and writing in the journal of the American Academy of Child and Adolescent Psychiatry, Peter Jensen from Columbia University and his colleagues stressed that “it would be incorrect to conclude from these results that treatment makes no difference or is not worth pursuing.”

Furthermore, since the study began back in the 1990’s, the therapies for the disorder, which have been dogged with concerns over safety and the potential for misuse, have moved on. For example, a hotly-anticipated new addition to the treatment menu could be Shire’s Vyvanse (lisdexamfetamine dimesylate), which was launched in the USA in July and could be rolled out in the UK next year. Excitement over the drug has been spurred by reports that it may have a lower potential for misuse than existing therapies on the market.

The UK’s cost-effectiveness body, the National Institute for Health and Clinical Excellence, is currently reviewing its guidance on the treatment of ADHD, and it is widely expected that when it comes it will be centred on a combination of approaches.

In the meantime, Baroness Susan Greenfield has asked the government during a session in the House of Lords what action it plans to take will take in the light of the findings of the MTA study.

She has called for an inquiry into the matter that not only assess the effectives of ADHD drugs but also the reasons behind the “remarkable increase” in the number of children diagnosed with the condition over the last two decades. “The time is ripe for an inquiry exploring the actual causes of ADHD that goes beyond merely evaluating the pros and cons of Ritalin,” she said in a statement.