A case study of unruly science

By Christopher Caldwell

If, say, William Brown, the school-shirking, mischief-prone hero of Richmal Crompton’s Just William stories, were passing through any school system in the English-speaking world today, he would be drugged to the gills. In the decades since Crompton wrote, Attention Deficit Hyperactivity Disorder (ADHD) – the name coined to describe a variety of unproductive and sometimes disruptive childhood behaviours – has become an American obsession. It is now diagnosed in countries other than the US, and in adults as well as children. It has spurred a market for drug treatments that exceeds $3bn annually in the US and could reach £101m ($207m) a year in the UK by 2012, according to recent projections carried out at the University of Heidelberg. A 10th of American boys, by some estimates, take some kind of anti-ADHD drug. “Since ADHD is only treatable, not curable,” ran one report in Medical Marketing and Media last year, “people take drugs for life, equalling a potential boon for pharmaceutical companies”.

The problem is that there is not a clear definition of what ADHD is. There is no test for it. The symptoms laid out in the mental-health diagnostic manual DSM-IV are vague enough (“often does not follow instructions”, “often loses things” etc.) to invite overdiagnosis. Against this will-o’-the-wisp, doctors have deployed the pharmacological equivalent of a howitzer. Most drugs used against ADHD are strong stimulants, either methylphenidates or amphetamines. They have been abused on US college campuses and carry risks of addiction, hallucinations, heart attacks and strokes. The US Food and Drug Administration has occasionally urged stronger warnings for ADHD drugs and, in 2005, Health Canada briefly suspended sale of the market leader (Adderall XR, made by Shire Pharmaceuticals). In the US, pharmaceutical companies have been faulted for aggressive advertising and lobbying. In the early 1990s, Ciba-Geigy (now Novartis) gave $748,000 to Chadd, a sufferers’ advocacy group that was then campaigning to relax regulation of Ciba-Geigy’s drug Ritalin.

So is ADHD a vital discovery or a popular folly? Andrea Bilbow, founder of the British ADHD charity Addiss, takes the first view. “The minute you raise awareness,” she said earlier this year, “you’re going to see an increase in diagnosis and treatment.” Indeed, the US follows this pattern; richer areas, with more knowledge about medical developments, are often more heavily medicated. But Australia – a country where ADHD medicines have been both widely prescribed and strongly resisted – belies it. In Sydney last year, The Daily Telegraph newspaper reported that children in rich neighbourhoods were given medication at one 12th the rate of children from poor ones. One in 300 children gets ADHD drugs in the wealthy north versus 1 in 25 in poorer areas.

The sceptics have lately been getting the better of the argument. This summer, a follow-up to the 1999 Multimodal Treatment Study of Children with ADHD (MTA) – which provides the main evidence for the effectiveness of drug therapy – rescinded a number of the study’s earlier conclusions. Gains from drug treatment evaporate after three years, the follow-up showed, and there is evidence that the drugs stunt children’s growth. William Pelham of the University of Buffalo, one of the researchers involved in the MTA study, said on BBC1’s Panorama on Monday that he now favours behavioural therapies because the familiar drug treatments offer “no beneficial effects – none”.

A fascinating neurological study published this week by the US National Institute of Mental Health holds out promise of resolving many controversies. The study looked at the way the right brain cortex, which helps control attention and planning, thickens during childhood. Scientists compared brain scans of hundreds of children diagnosed with ADHD with scans from a non-ADHD group. They found that, for non-ADHD children, the cortices reached maximum thickness at about 7½ years. For the ADHD group, that stage came three years later. But it did arrive eventually, and by puberty, most of the hyperactive kids had normal-looking brains.

This will hearten both those who say ADHD is a silent crisis and those who say it is a loud hoax. The report seems to suggest that ADHD is a neurological reality, but does not establish that it is, in the long term, either abnormal or permanent. This view was reinforced by a long-term behavioural study by a team of psychiatrists and educators, published in the November issue of Developmental Psychology. Attention skills at the time children entered school were found to be “modestly” associated with school achievement years later, but far less so than early maths and language mastery. Indeed, “socio-emotional behaviours” – presumably including the kind of “acting out” often associated with hyperactivity – “were generally insignificant predictors of later academic performance”.

In a time of scientific upheaval, innovations in treatment can outpace innovations in diagnosis. Sometimes the medical establishment is vulnerable to underdiagnosing, leaving people to suffer unnecessarily. But in recent years, there have been too many incentives to overdiagnose ADHD. Some are financial. Most are social and familial. The world has changed to the point where institutions and families lack the authority, inclination and manpower to handle the misbehaviour of any but the most tranquil pre-adolescent.

Is giving stimulants a sensible treatment for a serious disorder? Or is it just a means of controlling unruly children? We shall find out. The research of the NIMH promises a better understanding of ADHD and how to treat it. Whether that understanding will confirm or contradict our own is less clear.