If you want to stoke parental anxiety, there are few better ways than announcing a dramatic rise in the incidence of autism. That is exactly what happened at the weekend with a story that the incidence of autism was far higher than previously thought – as many as one in 58 children – with the MMR vaccine back in the dock as a possible culprit.

The story was the result of the leak of an unpublished report put together by a team of British scientists including Professor Simon Baron-Cohen, head of the Autism Research Centre at Cambridge University and one of the most authoritative figures in the field.

One of the two team members reported as resurrecting the discredited theory that MMR causes autism is Dr Carol Stott, a developmental psychologist who once worked at ARC. Baron-Cohen says she left ARC some time ago. She is now listed as a member of staff at Thoughtful House, a research centre in developmental disorders in Texas. Thoughtful House is run by Dr Andrew Wakefield, the gastroenterologist who first raised the possibility of a MMR-autism link in 1998. The other figure named as having revived the MMR-autism link was Dr Fiona Scott, who still works at ARC as an honorary research associate and runs training courses on how to diagnose autism. Scott has issued a statement denying that she privately believes in any link between MMR and autism.

Baron-Cohen says the news story is alarmist and wrong. He does not believe that MMR has anything to do with autism. “We are gobsmacked, really, at how this draft report has got out,” Baron-Cohen says. “It was only in the hands of the authors – about half a dozen people. There are three professors listed, including me, and none of us was contacted. It was also seen by two PhD students for whom I have the utmost respect because they are very careful scientists.

“I don’t believe that the MMR vaccine causes autism and I don’t believe that there are hidden environmental reasons for any rise in cases. For the moment, we should assume [any rise] is more to do with diagnostic practice.” Baron-Cohen says that health services are more geared towards early diagnosis, and there has been a broadening of the autism spectrum. Children that would have been thought eccentric or withdrawn a decade ago are now being given diagnoses such as Asperger’s syndrome, a high-functioning form of autism in which intellect is unimpaired but social interaction is compromised.

It transpires that Wakefield is up before the General Medical Council’s Fitness to Practise panel next week, on charges of serious professional misconduct. Two other doctors – Professor John Walker-Smith and Professor Simon Murch – who co-authored the original controversial 1998 Lancet paper with Wakefield, face similar charges, all relating to that single, disputed paper, which was later retracted. If found guilty, all face being struck off.

The draft report was leaked a week ahead of their GMC appearance. Baron-Cohen puts it like this: “We think it [the report] has been used. They’ve picked out the one figure that looks most alarmist.” Cambridge University is now trying to hunt down the source of the leak.

So, what are the facts on autism? Does the one-in-58 figure hold up? Baron-Cohen says their study of Cambridgeshire children, which has been running for five years, comes out with a range of figures from one in 58, to one in 200, depending on various factors. The draft report, he says, “is as accurate as jottings in a notebook”. He adds that the data is with public health officials, who are crunching the numbers.

A definitive number from the study, the professor hopes, will be published this year. It is possible that the one-in-58 figure comes from ARC’s use of the Childhood Asperger’s Syndrome Test (CAST), a questionnaire that parents can use to assess whether their child may have autism. The ARC team has used it on Cambridgeshire children in mainstream schools. However, it does not provide a diagnosis and is known to result in a high number of false positives. Around half the children flagged up by CAST as possibly having autism turn out not to.

In the meantime, he says that the best, most carefully conducted studies all show around 1 per cent of children lie on the autism spectrum (see box) and there is no reason to suspect that this has suddenly changed. There has been a gradual rise over decades, he says, but this reflects the fact that children are more routinely assessed, greater public awareness, and a wider diagnostic net.

The National Autistic Society also quotes a figure of 1 per cent for the incidence of autistic spectrum disorders. Benet Middleton, the NAS’s director of communications, says that, having spoken to Baron-Cohen, the charity had no plans to revise its figures. Middleton says: “This is an unpublished study that has not been peer-reviewed, and there are lots of reasons why studies don’t get published. The research that’s been published and peer-reviewed suggests a rate of 1 per cent.

“The news story made a connection between two unrelated issues [the incidence of autism and the MMR vaccine]. I don’t think that was a valid connection.” Middleton adds that the charity does not advise parents whether or not to have the MMR jab, but instead directs them to their GP.

Baron-Cohen says that the results will be published eventually: “We’ve been sitting on this data since 2005 because we wanted to get the best advice. There’s a number of different estimates for this population [the Cambridgeshire schoolchildren] depending on how you count. We need to work out which figures are the most reliable.

“Research is sometimes slow but it is better to go slowly and get it right. Now things have been taken out of our hands and it’s very dismaying.”

The range of disorders, what to look for and how they can be treated

Autistic spectrum disorders (ASD)

Autism is a complex and lifelong condition for which there is no cure. A comprehensive evaluation requires a multidisciplinary team including a psychologist, neurologist, psychiatrist, speech therapist and other professionals. Because hearing problems can cause behaviours that could be mistaken for autism, children with delayed speech development should also have their hearing tested.

Diagnosis

ASD can usually be diagnosed at the age of two. Some people may never obtain a proper diagnosis of their condition and still manage to live full and capable lives, but most will benefit from one because it brings relief, allows access to services and therapies, and aids family support.

Treatment

There is no cure, but the earlier a diagnosis is made the better the chances of appropriate management via therapy, educational programmes and support groups.

Atypical autism

Autism affects the way a person relates to people around them.

Traits include:

— Difficulty with social interaction (eg, appearing aloof)
— Difficulty with verbal and nonverbal communication (eg, words, gestures, expressions or tone of voice)
— Difficulty with social imagination (eg, a limited range of imaginative activities, possibly copied and pursued rigidly and repetitively)
— Sometimes, an accompanying learning disability

Asperger’s syndrome

Children with autistic behaviours but well-developed language skills are often diagnosed with Asperger’s syndrome

Traits include:

Like those with atypical autism, someone with Asperger’s syndrome also has difficulty in communicating, social relationships, and social imagination. It differs from atypical autism in the following ways:

— Social relationships: many people with Asperger’s syndrome enjoy human contact, although they find it hard to understand facial expressions
— Difficulty with communication: those with Asperger’s syndrome may speak fluently, but they may not understand reactions of those around them. They may also sound overprecise
— Lack of imagination: while they often excel at learning facts and figures, they can find it hard to think in abstract ways
— Special interests: they may also have an obsessive interest in a hobby and they often find change upsetting

Pervasive developmental disorder not otherwise specified (PDD-NOS)

Children with some symptoms of autism but not enough to be diagnosed with atypical autism or Asperger’s syndrome are often diagnosed with pervasive developmental disorder not otherwise specified (PDD-NOS). This term is only used when all other possible diagnoses have been eliminated and varies in meaning depending on the individual. Research is continuing into the possibility of positive criteria for PDD-NOS.

Source: www.nas.org.uk

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