Hidden dangers of failure to diagnose ADHD correctly

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http://www.newscientist.com/channel/opinion/mg19025451.800

Hidden dangers of failure to diagnose ADHD correctly

01 April 2006

NewScientist.com news service

IT SOUNDS like a mad idea, but it works. Take children who are unruly and

unable to focus on their schoolwork, and give them amphetamine-like

stimulants. Far from making them bounce off the walls, the drugs can turn

little terrors into attentive students.

However, the idea of prescribing drugs related to addictive illegal

stimulants has always caused concern - all the more so given the escalation

in diagnoses of attention deficit hyperactivity disorder (ADHD), the

condition the drugs are supposed to treat. Now reports are coming in of

serious adverse reactions, including hallucinations and, in rare suspected

cases, sudden death from cardiovascular problems (see " Hyperactivity drugs

are out of control " ).

For the benefit of concerned parents, it is important to put the risks and

benefits into context. ADHD is a socially and educationally debilitating

condition, and places children at higher risk of serious accidents. The

success of stimulants such as methylphenidate in treating ADHD is

unprecedented in psychiatry. Unlike antidepressants, which work well in only

about half of those who take them, methylphenidate is highly effective in

most children and young adults with ADHD. Against these benefits, we now

have 25 cases of sudden death from heart problems, and reports of

hallucinations in up to 5 per cent of those taking the drugs.

These adverse events certainly need further investigation, and merit changes

to the drugs' labelling so that doctors and patients can see the risks. Yet

on existing evidence, the drugs should not be demonised. Instead, we should

make sure that they are only given to children who actually have ADHD,

because that is where the main problem lies. Proper diagnosis requires

extensive behavioural observation, ideally in different contexts. Some kids

are unfocused and unruly at home, yet can buckle down at school with a good

teacher. Medicating kids because of bad parenting is a bad idea.

Some 10 per cent of 12-year-old boys in the US, where diagnosis of ADHD is

more common than in most other countries, are being treated for the

condition. The true incidence of the disease may well be very high, but

these figures conceal widespread misdiagnosis. Many children who do not have

ADHD are prescribed the drugs after woefully short consultations, often by

family doctors under pressure from parents who want their children to

compete in the classroom. Yet other youngsters who have ADHD are not getting

the treatment they need.

This in microcosm is what is wrong with the US healthcare system, which

tends to over-medicate those who have health insurance, leaving the rest to

make do with healthcare that would embarrass some developing countries. Even

so, the situation with ADHD is particularly worrying, as both

over-medication and under-medication could lead to future drug dependency.

Children with untreated ADHD are known to be at greater risk of later drug

abuse than those on medication. The impact of giving stimulants to healthy

kids is unknown, and difficult to study. Despite efforts by manufacturers to

formulate pills to release their active ingredient slowly, minimising their

addictive potential, the fear remains that today's prescribing practice may

be priming millions of children for drug-dependency problems.

In this context, the decision last week by advisers to the US Food and Drug

Administration not to back an application to market a drug for ADHD called

modafinil has caused some disappointment. Modafinil should not be addictive,

but the FDA's advisers were concerned about a case of a serious skin

condition in a clinical trial, and have asked for further studies. The FDA

advisory panel's caution is appropriate. Yes, we need other drugs to treat

ADHD. But first we must be sure they are safe, and are only given to

children who really need them.

From issue 2545 of New Scientist magazine, 01 April 2006, page 5