The autism epidemic that never was

RICHARD Miles will never forget the winter of 1989. The 34-year-old company director and his family spent that Christmas on the island of Jersey in the English Channel, where he had grown up. It was also then that he first noticed something was badly wrong with his 14-month-old son Robert. The bright, sociable child, who had already started talking, became drowsy and unsteady on his feet. Then he started bumping into furniture. Within weeks his language had dried up and he would no longer make eye contact. "It was as if the lights went out," says Miles. His son was eventually diagnosed with autism.

Miles, who now campaigns for more research into autism, is convinced that his son is part of an autism epidemic. Ten years ago, he points out, Jersey had just three autistic children in special-needs education. It now has 69. Robert was one of a cluster of nine children on the island diagnosed around the same time.

Similar rises have been reported across the world, from Australia to the US, and from Denmark to China. Back in the 1970s, specialists would typically see four or five cases of autism in a population of 10,000. Today they routinely find 40, 50 or even 60 cases. Perhaps the starkest illustration of autism's relentless rise comes from California. In 2003, the state authorities stunned the world when they announced that over the previous 16 years, the number of people receiving health or education services for autism had risen more than sixfold. The world's media went into overdrive.

What could be causing so many children to lose their footing on a normal developmental trajectory and crash-land into the nightmare world of autism? The change has occurred too suddenly to be genetic in origin, which points to some environmental factor. But what? There is no shortage of suspects. In the UK, blame is often laid at the door of the combined measles, mumps and rubella (MMR) vaccine. In the US, mercury added to a range of childhood shots has been accused. Food allergies, viral infections, antibiotics and other prescription drugs have all been fingered, often by campaign groups run by mystified and angry parents. The problem is that none of these suggested causes has any solid scientific evidence to support it (see "The usual suspects").

Perhaps there's a simple explanation for this: there is no autism epidemic. On the face of it that sounds ridiculous - just look at the figures. But talk to almost any autism researcher and they will point to other explanations for the rise in numbers. Some say it's still an open question, but others are adamant that the autism epidemic is a complete myth. And if the most recent research is anything to go by, they could be right. Studies designed to track the supposedly increasing prevalence of autism are coming to the conclusion that, in actual fact, there is no increase at all. "There is no epidemic," says Brent Taylor, professor of community child health at University College London.

Autism is a developmental disorder sometimes noticeable from a few months of age but not usually diagnosed until a child is 3 or 4 years old. It is characterised by communication problems, difficulty in socialising and a lack of imagination (see "What is autism"). It is not a single disorder, but comes in many forms, which merge into other disorders and eventually into "normality". There is no biochemical or genetic test, so diagnosis has to be made by observing behaviour. Autistic children also often have other medical conditions, such as hyperactivity, Tourette's syndrome, anxiety and depression. The upshot is that "one person's autism is not another person's autism," says epidemiologist Jim Gurney of the University of Minnesota in Minneapolis.

In recognition of this ambiguity, autism is considered part of a continuum within a broader class of so-called "pervasive developmental disorders" (PDDs) - basically any serious abnormality in a child's development. Autism itself is divided into three categories: autistic disorder, Asperger's syndrome (sometimes called "high-functioning autism"), and pervasive developmental disorder-not otherwise specified (PDD-NOS), sometimes called mild or atypical autism. Together these three make up the autistic spectrum disorders.

Confused? You're not the only one. The difficulty of placing children with developmental problems on this spectrum has led to several major shifts in the way autism is diagnosed in the past 30 years. In the late 1970s, the autism label was kept for those with severe problems such as "gross language deficits" and "pervasive lack of responsiveness". But since 1980 the diagnostic criteria have been revised five times, including the addition of PDD-NOS in 1987 and Asperger's in 1994.

This massive broadening of the definition of autism, particularly at the milder end of the spectrum, is one of the main factors responsible for the rise in cases, says Eric Fombonne of McGill University in Montreal, Canada, a long-standing sceptic of the epidemic hypothesis. Tellingly, around three-quarters of all diagnoses of autism today are for Asperger's and PDD-NOS, both of which are much less severe than the autism of old. "There is no litmus test for who is autistic and who is not," says Tony Charman of the Institute of Child Health at University College London.

Changes in diagnostic criteria apart, there are other reasons to believe that autism is simply being diagnosed more often now than in the past. One is the "Rain Man effect" - the huge increase in the public awareness of autism following the 1988 film starring Dustin Hoffman. Awareness has also increased massively among healthcare workers. "Twenty years ago there were maybe 10 autism specialists in the country. Now there are over 2000," says Taylor.

Another factor is that one of the stigmas of autism has largely disappeared. Until about 10 years ago a prominent idea was that autism was caused by an unloving "refrigerator mother". Now it is a no-blame disease. "Parents are more willing to accept the label," says Taylor. One expert New Scientist spoke to went as far as to describe autism as "trendy".

Finally, while some parents still have to fight for help for their autistic children, far more services are now available. This has encouraged doctors to label borderline or ambiguous cases as autism - they know this is often the best way to get the child some help. It also makes autism an attractive diagnosis for parents. "I hear stories of parents who are anxious to get a particular diagnosis if that is what is required to obtain the services their child needs," says Sydney Pettygrove, a paediatrician at the Arizona Health Sciences Center in Tucson. In the UK, says Simon Baron-Cohen of the Autism Research Centre at the University of Cambridge, "in every town there are trained clinicians who can make a diagnosis."

It is hard to quantify these trends, but many epidemiologists now believe that they can account for the apparent rise in autism the general public and media take for granted. Proving it, however, is difficult - if not impossible. The main problem is that an epidemiological study carried out in the 1980s simply cannot be compared with one done last week. There will be so many differences in diagnostic procedures and in the willingness of doctors and parents to label a child autistic that comparisons are meaningless. "You can't control for everything," says Charman.

And so attention has shifted to what epidemiologists sniffily refer to as "service provider data", such as the California figures. Ever since 1973, the authorities there have been keeping records of the number of people receiving some kind of state help in connection with autism. In 2003, California's Department of Developmental Services (DDS) announced a chilling figure that captured the world's attention. In the 16 years to 2002, cases rose from 2778 to 20,377 (see Graph). Among autism campaigners these figures are often cited as incontrovertible and final proof of the existence of the autism epidemic.

But there are serious problems with this interpretation. First, the figures are raw numbers from public services, not a proper epidemiological study. Critics point out they are not corrected for changes in diagnostic criteria or for the growing awareness of autism.

There is evidence, for example, that as the California autism numbers have risen, diagnoses of mental retardation have fallen. Researchers at Boston University School of Medicine in Massachusetts have found a similar pattern in the UK. This effect, dubbed "diagnostic substitution", cannot explain all the increase but is one example of how diagnostic fashions can skew the data.

Another potential flaw is that the California figures don't take into account the fact that the state's population is growing rapidly. Between 1987 and 1999, the total population rose by nearly 20 per cent, and the age group 0 to 14 rose even more steeply, by 26 per cent.

As a result of these doubts and unknowns in the California figures, most epidemiologists refuse to draw firm conclusions from them. "The report doesn't change anything," says Charman. "It's not a systematic study." In fact, the preface of the most recent California report contains a health warning not to read too much into the numbers. "The information should not be used to draw scientifically valid conclusions," it says.

Some researchers, notably Robert Byrd of the MIND Institute at the University of California, Davis, have attempted to correct for all the unknowns. In an analysis published on the state DDS website nearly three years ago, Byrd concluded that the rise is real. "Autism rates are increasing," he told New Scientist. Some scientists accept that Byrd's analysis lays to rest the idea that population growth could have significantly swelled the figures. But his methods for investigating the other potential sources of bias have been heavily criticised, and tellingly, Byrd has not yet succeeded in getting his study published in a peer-reviewed journal. Until he does, it is hard to know how much weight to give his conclusions.

Perhaps the strongest case against the "better diagnosis" theory is that, if true, there should be a "hidden hoard" of autistic adults who were never properly diagnosed in childhood. To parent Richard Miles, this is compelling. "My doctor cannot believe that he could have missed so many cases in the past," he says. But Taylor disagrees. As a former general practitioner, he says there are many children today diagnosed with autism who would not have been labelled as such in the past.

This view is difficult to substantiate, but in 2001 a team led by Helen Heussler of Nottingham University, UK, had a crack. They re-examined the data from a 1970 survey of 13,135 British children. The original survey found just five autistic children, but using modern diagnostic criteria Heussler's team found a hidden hoard of 56. That's over a tenfold rise in numbers, which puts the California figures in perspective. Heussler and her colleagues concluded that "estimates from the early 1970s may have seriously underestimated the prevalence".

Lorna Wing, a veteran autism researcher at the Institute of Psychiatry in London, agrees. In the 1970s she spent a lot of time working with special-needs children in the London district of Camberwell. Wing reckons that at the time, fewer than 10 per cent of autistic children were correctly diagnosed. She also thinks that prisons and institutions are full of autistic adults labouring under wrong diagnoses such as treatment-resistant schizophrenia or ADHD.

Ultimately, however, it may be impossible to tell whether there has been a genuine rise in the incidence of autism over the past 30 years. "There is no clear evidence that there has been an increase, but there's no proof that there hasn't," says Charman. Even the arch-sceptic Fombonne accepts this. "We must entertain the possibility," he says. "But we don't have the evidence."

But researchers can answer another question: is the incidence of autism continuing to rise? There is a tried and tested method of tackling this sort of question. You carry out a large prevalence study among a particular age group, and then repeat it a few years later with a new set of individuals, in the same place and using exactly the same methods. Several such studies into autism are ongoing, notably one funded by the US Centers for Disease Control and Prevention in Atlanta, which will look at changes in incidence across 11 states.

One team, however, is ahead of the game. Back in July 1998, Fombonne and Suniti Chakrabarti of the Child Development Centre in Stafford, UK, started screening every child born in a four-year window (1992 to 1995) who lived in a defined area of Staffordshire, 15,500 children in total. As a result, they established baseline figures for autistic spectrum disorders - about 62 per 10,000. Then they did it again, in exactly the same place and exactly the same way, this time with all the children born between 1996 and 1998. In June this year, they reported that the prevalence of autism was unchanged (American Journal of Psychiatry, vol 162, page 1133). "This study suggests that epidemic concerns are unfounded," concludes Fombonne.

Similar surveys need to be done in other parts of the world to rule out the possibility that there is something unusual about Staffordshire. And the Staffordshire result has failed to convince campaigners and parents, including Miles. But what is clear is that after the first direct test of whether autism is rising, it's 1-0 to the sceptics.

That doesn't mean we should stop searching for the causes of autism. The disorder itself is real, and if researchers knew what was behind it much suffering could be averted. But the Staffordshire surveys do suggest that there is no environmental problem that is triggering autism in ever-greater numbers and which must be identified as a matter of urgency. That will not be much comfort to families with autistic children. But it should make everyone else feel a bit more secure.

What is autism?

The developmental disorder that is now called autism was first described by doctors in 1943. Psychiatrists say there are three key features: lack of imagination, communication difficulties, and problems interacting with others. In practice, those affected have a bewildering range of strange behaviours. These can include fear of physical contact, hearing and visual problems, bizarre obsessions and a touching inability to lie.

Apart from the fact that about three-quarters of those affected are male, it is hard to make generalisations because the condition varies widely between patients. Contrary to popular belief, freakish talents for maths or music, say, are uncommon. In fact, about three-quarters of people with autism have learning difficulties, but those who do not may manage to hold down a job.

Parents usually realise something is wrong because children fail to develop normally. But up to one third of cases are "regressive" - children seem to go backwards when they are about two, losing their language and social skills.

In psychological terms, people with autism seem to lack "theory of mind" - the recognition that other individuals may hold a different perspective on things than themselves. This leaves them in a bewildering world where people seem to act according to incomprehensible rules and behave in meaningless ways. They also have impaired "executive function", the ability to plan future actions. And patients have weak "central coherence", the ability to extract meaning from experiences without getting bogged down in details. In other words, they can't see the wood for the trees.

The usual suspects

Both genes and environmental factors play a role in the development of autism. But if there has indeed been a sudden rise in cases, the only possible cause is an environmental change because our genes can't be altering that fast. Numerous candidates have been proposed.

Thanks partly to anecdotal reports linking autism with bowel problems, some researchers believe that the condition could be caused by various dietary components leaking through the gut wall into the bloodstream, allowing them to reach the brain. One possible cause could be increased use of antibiotics disturbing the natural balance of gut bacteria.

There have been some reports of people with autism doing better on diets that exclude dairy foods and gluten, a protein found in wheat and barley. And a few small studies have found that some patients seem to improve after injections of the gut hormone secretin, which could possibly be related. But neither of these approaches have been borne out by larger placebo-controlled trials.

The combined measles, mumps and rubella (MMR) vaccine was fingered by gastroenterologist Andrew Wakefield, formerly of the Royal Free Hospital in London. He suggested that giving children three vaccines simultaneously could damage their gut. Along with vociferous campaigning by parents, this led to a fall in uptake in the UK of this important childhood vaccine.

However, numerous large-scale studies showed no link between receiving the vaccine and developing autism. A recent study from Japan may prove the final nail in the coffin for the MMR theory. It found that diagnosed cases in that country continued to rise even after the triple jab was withdrawn (Journal of Child Psychology and Psychiatry, vol 46, p 572).

In the US, mercury is public enemy number one. The mercury-containing preservative thimerosal - which has been used in a range of childhood vaccines although it is now being phased out - is claimed to cause autism by damaging the developing brain directly. But a review last year by the US Institutes of Medicine rejected a causal link between autism and either mercury or the MMR jab.

We have a friend whose little boy is truly autistic. He was fine until about 2 yrs. old and then all progress stopped and he began to regress.

I also am the parent of a special needs son (Down Syndrome) and in his travels I have seen truly autistic kids - there's no doubt about it - they've got a problem. From my perspective, raising an autistic kid seems one of the toughest parental rows to hoe.

I personally think there has been an increase in true autism. My wife suggests maybe some kids just got labeled "retarded" in the old days. I don't know, but clearly there are more truly autistic kids than there used to be. I figure there is something to the vaccine or food allergy theory.

However, I'm also a grandfather who coaches an elementary age basketball team, so I see all different types of kids. A lot of kids are diagnosed with PDD who are developmentally normal in my opinion. It's my impression that the one thing these kids (boys who are able to play on a mainstream basketball team) have in common is weak parents who are always trying to reason with their kids instead of parenting them. I don't meet a lot of working class kids with PDD.

I was talking to my daughter-in-law about this article. She teaches Special Ed. Her opinion mirrors mine. The one thing she did say though that was very interesting to me was that the vast majority of truly autistic kids started out developing normally. Then their parents report development just suddenly stopped and slowly began to reverse. She laughed about the word trendy being used for autism. She said she and her colleague break the autistic kids into two groups: "really PDD" and "rich kid PDD".

Domestic Church

I understand your criticism but it's actually more complex than you make it.

The schools were saddled with the education of special education by the IDEA act in 1974; shortly after the states reduced the populations of their mental institutions by dropping off their patients on the streets. These were dark days for the mentally disabled indeed.

Now there are some schools, particularly in liberal controlled districts, that do have a habit of reclassifying troublesome students as special education students. These students do get extra money and are removed from the rolls of standardized test taking thus helping the school look better as well.

However, you generalize from this situation to the more general situation of special education. I, and other parents of Autistic children, can assure you that the school districts would prefer to have nothing to do with our truly disabled children. The money supplied by any federal programs doesn't even begin to cover the appropriate methodology to help profoundly Autistic children so they will be less of a burden on society later in life. Thus, we are a scourge, stealing from their general budget.

So who is looking to expand the definition of Autism and why? It's organizations like NAAR, CAN, FEAT, COSAC and more that are doing so. I am a member of two of those organizations. These are organization developed to first help parents deal with their disabled children and then find out how they became that way. Without research, there can be little insight into why Autistic children are they way they are. However, there is lots of competition for research funds whether it's from public or private sources. What the leaders of these organizations discovered was that there was a ton of public money being spent on non-existent global warming or on diseases like AIDS that have known methods for prevention (alas, not followed).

When research is done with federal funds, it becomes part of the public domain and the above mentioned organizations can then affordably scrutinize the data to find insight. Thus, these organizations have INFLATED the number of children covered in the Autism spectrum. Since my son was diagnosed 5 years ago, the number of Autistic children went from 1 in 500 to 1 in 50. This is on the face of it preposterous. And as the father of a son profoundly affected by Autism, it disturbs me that so many relatively normal kids are lumped in the same diagnosis.

That said, the reason the diagnosis inflation is done is the same reason the military asks for thousands of armored humvees in hopes of getting a few hundred. Without these types of numbers, research dollars will otherwise flow into studies on cow flatulence. I don't like the game, I'm just a player.

Would I prefer that charitable organizations be used to benefit my son rather than imposing on the fine taxpayers of my town and the United States. You bet!!! However, my son needs my help now and a method to get to a point that he can survive when I'm dead. The federal government has been usurping the place of church and charity for more years than I've been alive. I want to change the system but I want to help my son more. A conundrum for a FReeper like me but one on which I will fall to the side of favoring my son.

Here we go ... this is the problem. People who will, now due to this foolish article, down play the true problem that exist. This article in my mind is worthless. Just another, how we can sweep away the issue under a rug.

I have a son with autism. Prior to my son reaching to the age of 3 years old, I had not a single clue of what was autism. We took him to 2 pediatricians, both of whom said he was fine and that my son was a late bloomer. The same crap I got from family members stating ... "don't worry, boys take longer to talk than girls".

Not until I saw, a news program concerning the rise in Autism and they listed the symptoms (most of which he matched).

- Him being nonverbal, the spinning, banging his head on the wall, the appearance of almost being deaf (due to unresponsiveness), the arm flapping, the lining up of toys in a straight line over and over again, the no making eye contact, and the list goes on.

As clear as day, it hit me what my son had. I was like a double edge sword. It was great that I now know what he has (I can now give it a name and others would understand) but it truly sucks that he has it. My wife was in denial. I don't blame her, who would want to know that there child has a brain defect (and that what it truly is).

I have read almost every article I can find on the subject. I am part of many different groups on the subject. All in hope that I can find a cure for my son.

But when, I see articles like this, it makes me angry. Trying to brush off or lightly coat this problem. After, I learned what the Autism spectrum was, I would spot an autistic child and even adults a mile away.

I know of at least 3 families, who due to contact via my children's school or my work, have autistic children. But they are in denial and don't want to take action. And now because of articles like this, they probably won't.

Sadly, no one has the cure or answer to what causes autism. This BS about, well in the UK from this time period compared to another time period there was no rise. That's just hogwash. Can someone explain to me why is it that based on some articles there are very few people with autism in the Amish community (here's the link http://washingtontimes.com/upi-breaking/20050508-112601-3643r.htm )?

OK, maybe you want to say ... well the Autism of today is not the same as of yesterday. Fine. But don't tell me that there isn't still a problem. And it's not just called Autism, it's called the autism spectrum disorder. Which means that a person can fall within a spectrum of this disorder. Some have it more severe than others. Thank God my child is on the high functional end, meaning that he has it mildly. But nonetheless, he is autistic and has mental problems.

I would give my right arm (seriously) to have my son not have this. He's a great kid. But it hurts that as much love and affection that I have for him, he just gives me blank stares. I am accepting of him and all that he does, but I know society would rather ridicule and brush him aside.

For all those nay sayers who claim that this is not an epidemic and a true problem. I would hope that you bear a child with autism (since it's not a problem) so that you can walk in my shoes. I am willing to bet the author of this worthless article doesn't have an autistic child.

Sounds very similar to my experience and my sentiments.

I, too, get sick of people claiming there is no problem. (I forgot my sarcasm tags in my original post).

I would give my right arm (seriously) to have my son not have this. He's a great kid. But it hurts that as much love and affection that I have for him, he just gives me blank stares. I am accepting of him and all that he does, but I know society would rather ridicule and brush him aside.

Well said. I'm right there with you. We'll just keep loving these kids, and doing what we can for them, whatever the eggheads say and whatever the politicians don't do.

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