Autism Series 2013 – Part 3: The Autism “Epidemic”

Weintraub, K., Autism counts. Nature, 2011. 479(7371): 22-4.

Weintraub, K., Autism counts. Nature, 2011. 479(7371): 22-4.

It seems that autism is on the rise.  Once hidden away in institutions or just dismissed as odd, society is now faced with a condition that it is yet to come to grips with.  Some out in the community believe that it must be a toxin, or vaccines or mercury.  Others accuse doctors of simply giving in to the unreasonable demands of pushy parents to defraud the system of money – “Things have reached the point these days where any kid that’s not a charming little extrovert will be accused of being, ‘on the spectrum.’”[1]

So is there an epidemic of kids who are “not charming little extroverts”?  It depends on who you ask.

Take, for example, two articles written in the year 2000.  In the first, titled “The autism epidemic, vaccinations, and mercury”, Rimland said,

“While there are a few Flat-Earthers who insist that there is no real epidemic of autism, only an increased awareness, it is obvious to everyone else that the number of young children with autism spectrum disorders (ASD) has risen, and continues to rise, dramatically.”[2]

The other, written by Professor Tony Attwood, a world authority on Aspergers Syndrome, said,

“… is there an epidemic of people being diagnosed as having Asperger’s Syndrome? At present we cannot answer the question, as we are unsure of the diagnostic criteria, the upper and lower levels of expression and the borders with other conditions. Nevertheless, we are experiencing a huge increase in diagnosis but this may be the backlog of cases that have been waiting so long for an explanation.”[3]

I don’t think it’s very often Prof Attwood is lumped with ‘flat-earthers’.  But you can see the change in perspective from one side looking objectively to the other who need for there to be an “epidemic” of autism in order to strengthen their case.

So who’s right?  To see if this autism “epidemic” hypothesis has any real merit, we need to delve into some numbers.

First, some basic epidemiology – because part of the confusion in looking at the autism numbers is defining exactly what those numbers represent.  Here are some important epidemiology terms from the “Physicians Assistant Exam for Dummies”[4]:

Incidence: For any health-related condition or illness, incidence refers to the number of people who’ve newly acquired this condition.

Prevalence: Prevalence concerns the number of people who have this condition over a defined time interval.

Most autism figures are for prevalence, or often more specifically, point prevalence – “the number of people who have this condition at any given point in time.”

The other thing to remember from my last blog is that initially autism was only diagnosed on the strict rules of Kanner, and was considered to be a single disease caused mainly by bad parenting [5].  So through the 1960’s and 1970’s, only the most severe children were diagnosed as having autism because the high-functioning autism would not have met Kanners criteria, and even if they did, most parents didn’t want the label for fear of the social stigma.

So then, what are the numbers?  The early prevalence was estimated to be less than 5/10,000 or 1 in 2000[6], although in surveys done after 1987, the numbers began to rise past 7/10,000[7].  In the 1990’s, Autism prevalence climbed into the teens and the latest prevalence has been documented for autism is 20.6/10,000[7].

But that’s only about 1 in 485.  The CDC estimated a prevalence of 1 in 88 (113/10,000)[8].  Where did the other 400 people go?

This is where the importance of definitions is highlighted.  Autism is considered part of a spectrum, and at the time of the surveys reviewed by Fombonne, DSM III then DSM IV considered conditions like Pervasive Developmental Disorder and then Aspergers Disorder to be part of that spectrum.  Adding in the rate of PDD and you have a figure of 57.7/10,000 and adding in Aspergers gives you a combined rate of 63.7/10,000, or 1 in 157 people surveyed[7].

And yet even then, who you measure and how you measure makes much more of a difference, because a recent, rigorous study targeting all 7 to 12 year old children in a large South Korean populous found a prevalence of 2.64%, which is 264/10,000 or 1 child in every 38.  The authors noted that, “Two-thirds of ASD cases in the overall sample were in the mainstream school population, undiagnosed and untreated. These findings suggest that rigorous screening and comprehensive population coverage are necessary to produce more accurate ASD prevalence estimates and underscore the need for better detection, assessment, and services.”[9]

So if there has been a fifty-fold change in prevalence (from 5 to 264 cases per 10,000 people) in just thirty years, isn’t that an epidemic?

Well, no.  As much as some might ignorantly deny it, there is no real evidence for it.  Remember the definitions from the “Physicians Assistant Exam for Dummies”[4]:

Incidence: For any health-related condition or illness, incidence refers to the number of people who’ve newly acquired this condition.

Prevalence: Prevalence concerns the number of people who have this condition over a defined time interval.

It’s the rapid rise in the number of new cases diagnosed that defines an epidemic, which is the incidence and not the prevalence[10].  While the prevalence has changed a lot, the incidence has been fairly stable.  From Nature, “Christopher Gillberg, who studies child and adolescent psychiatry at the University of Gothenburg in Sweden, has been finding much the same thing since he first started counting cases of autism in the 1970s. He found a prevalence of autism of 0.7% among seven-year-old Swedish children in 1983 and 1% in 1999. ‘I’ve always felt that this hype about it being an epidemic is better explanation’, he said.”[11]

Fombonne agrees. “As it stands now, the recent upward trend in estimates of prevalence cannot be directly attributed to an increase in the incidence of the disorder.”[7]  He said later in the article that a true increase in the incidence could not be ruled out, but that the current epidemiological data which specifically studied the incidence of autism over time was not strong enough to draw conclusions.

While there’s no epidemic, there is the real issue of the genuinely increasing prevalence.  Why the rise in those numbers?  Fombonne went on to explain, “There is good evidence that changes in diagnostic criteria, diagnostic substitution, changes in the policies for special education, and the increasing availability of services are responsible for the higher prevalence figures.”[7]  Nature published a graph from the work of Professor Peter Bearman, showing that 54% of the rise in the prevalence of autism could be explained by the refining of the diagnosis, greater awareness, an increase in the parental age, and clustering of cases in certain geographic areas.

Weintraub, K., Autism counts. Nature, 2011. 479(7371): 22-4. (Adapted from King, M. and Bearman, P., Diagnostic change and the increased prevalence of autism. International Journal of Epidemiology, 2009. 38(5): 1224-34 AND King, M.D. and Bearman, P.S., Socioeconomic Status and the Increased Prevalence of Autism in California. Am Sociol Rev, 2011. 76(2): 320-46.)

Weintraub, K., Autism counts. Nature, 2011. 479(7371): 22-4. (Adapted from King, M. and Bearman, P., Diagnostic change and the increased prevalence of autism. International Journal of Epidemiology, 2009. 38(5): 1224-34 AND King, M.D. and Bearman, P.S., Socioeconomic Status and the Increased Prevalence of Autism in California. Am Sociol Rev, 2011. 76(2): 320-46.)

From Nature: “The fact that he still cannot explain 46% of the increase in autism doesn’t mean that this ‘extra’ must be caused by new environmental pollutants, Bearman says. He just hasn’t come up with a solid explanation yet. ‘There are lots of things that could be driving that in addition to the things we’ve identified,’ he says.”[11]

There is no autism epidemic, just medical science and our population realising just how common autism is as the definition becomes more refined, people become more aware, and some other biosocial factors come into play.

What can we take from the numbers?  That we’re being overtaken by Sheldon clones?  That soon there will be no more “charming little extroverts”?  If the CDC figure is accurate, then one person in every hundred is on the spectrum, so the world is hardly being overtaken by autism.  But the take home message is that Autism Spectrum Disorders are more common that we ever thought, and there are more people on the spectrum “hiding in plain sight”.  If the study from South Korea is accurate then one person in every thirty-eight is on the spectrum, but two thirds of them are undiagnosed.

Should there be more funding, more resources, or more political representation for people on the spectrum?  Perhaps, although the public and research funds are not unlimited, and other health concerns should also be treated fairly.  But since autism is life long and impacts on so many areas of mental health and education, understanding autism and managing it early could save governments billions of dollars into the future.

Rather, I think that the climbing prevalence of ASD is a clarion call for understanding and tolerance.  If we learn to tolerate differences and practice discretionary inclusion, then both the autistic and the neuro-typical can benefit from the other.  That’s a world which we’d all like to live.

REFERENCES

1. Bolt, A. If the autistic don’t get full cover, where’s the money going? 2013  2013 May 11]; Available from: http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comments/if_the_autistic_dont_get_full_cover_wheres_the_money_going/.

2. Rimland, B., The autism epidemic, vaccinations, and mercury. Journal of Nutritional and Environmental Medicine, 2000. 10(4): 261-6.

3. Attwood, T., The Autism Epidemic: Real or Imagined, in Autism Aspergers Digest2000, Future Horizons Inc: Arlington, TX.

4. Schoenborn, B. and Snyder, R., Physician Assistant Exam For Dummies. 2012: John Wiley & Sons.

5. Pitt, C.E. Autism Series 2013 – Part 2: The History Of Autism. 2013  [cited 2013 2013 Aug 15]; Available from: https://cedwardpitt.com/2013/08/15/autism-series-2013-part-2-the-history-of-autism/.

6. Rice, C.E., et al., Evaluating Changes in the Prevalence of the Autism Spectrum Disorders (ASDs). Public Health Reviews. 34(2).

7. Fombonne, E., Epidemiology of pervasive developmental disorders. Pediatric research, 2009. 65(6): 591-8.

8. Baio, J., Prevalence of Autism Spectrum Disorders: Autism and Developmental Disabilities Monitoring Network, 14 Sites, United States, 2008. Morbidity and Mortality Weekly Report. Surveillance Summaries. Volume 61, Number 3. Centers for Disease Control and Prevention, 2012.

9. Kim, Y.S., et al., Prevalence of autism spectrum disorders in a total population sample. American Journal of Psychiatry, 2011. 168(9): 904-12.

10. “Epidemic vs Pandemic”. 2013  [cited 2013 Sept 03]; Available from: http://www.diffen.com/difference/Epidemic_vs_Pandemic.

11. Weintraub, K., Autism counts. Nature, 2011. 479(7371): 22-4.

 

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Autism Series 2013 – Part 2: The History Of Autism

“We can chart our future clearly and wisely only when we know the path which has led to the present.” Adlai E. Stevenson

I always thought history was boring, and I must admit, If you want to put me to sleep, start reading early Australian history to me. “Convicts … first fleet … zzzzzz.”

But as Stevenson wrote, the key to the future is the past. With autism, I don’t want to see a future as checkered as its past. In this series of essays, I want to help our community see a future in which autism is recognised and appreciated for its strengths. To properly lay the groundwork, I want to look at the history of autism. This will help provide context for the current understanding of autism, which will then give a framework for understanding the autistic person, and for a glimpse into the future as new research unfolds.

The autistic spectrum has been present for as long as humans have. But to our knowledge, one of the first specific descriptions of someone who met the characteristics of the autistic spectrum was in the mid 1700’s. In 1747, Hugh Blair was brought before a local court to defend his mental capacity to contract a marriage. Blair’s younger brother successfully had the marriage annulled to gain Blair’s share of inheritance. The recorded testimony describes Blair as having the classic characteristics of autism, although the court described him at the time as lacking common sense and being afflicted with a “silent madness”.[1]

Isolated case reports appeared sporadically in medical journals. John Haslam reported a case in 1809, although with modern interpretation, the child probably had post-encephalitis brain damage rather than true autism. Henry Maudsley described a case of a 13 year old boy with Aspergers traits in 1879. There were no other reports of children with autism in the early literature, although at the turn of the 19th century, Jean Itard reported on the case of an abandoned child found roaming in the woods like a wild animal. This child, called Victor, displayed many features of autism, although he may have simply had a speech disorder. Either diagnosis was obscured by the effects of severe social isolation.[1]

Others described syndromes which shared autistic features, but without describing autism itself. The names given to each syndrome reveals how autistic features were regarded in the 19th century: Dementia Infantalis, Dementia Praecocissima, Primitive Catatonia of Idiocy.[1]

Around 1910, Eugen Bleuger was a Swiss psychiatrist who was researching schizophrenic adults (and as an aside, Bleuger was the person to first use the term ‘schizophrenia’). Bleuger used the term ‘autismus’ to refer to a particular sub group of patients with schizophrenia, from the Greek word “autos,” meaning “self”, describing a person removed from social interaction, hence, “an isolated self.”[2]

But it wasn’t until the 1940’s that the modern account of autism was articulated, when two psychiatrists in different parts of the world first documented a handful of cases. Leo Kanner documented eleven children who, while having variable presentations, all shared the same pattern of an inability to relate to people, a failure to develop speech or an abnormal use of language, strange responses to objects and events, excellent rote memory, and an obsession with repetition and sameness[3].

Kanner thought that the condition, which he labelled ‘infantile autism’, was a psychosis[1] – in the same family of disorders as schizophrenia, although separate to schizophrenia itself[2]. He also observed a cold, distant or anti-social nature of the parents relationship towards the child or the other parent. He thought this may have contributed (although he added that the traits of the condition were seen in very early development, before the parents relationship had time to make an impact)[3]. True to the influence of Freud on early 20th century psychiatry, Kanner said of the repetitive or stereotyped movements of autistic children, “These actions and the accompanying ecstatic fervor strongly indicate the presence of masturbatory orgastic gratification.”[3]

Despite the otherwise reserved, cautious discussion of possible causes of this disorder, the link with schizophrenia and “refrigerator mothers” took hold in professional and lay communities alike. In the 1960s and 70s, treatments for autism focused on medications such as LSD, electric shock, and behavioral change techniques involving pain and punishment. During the 1980s and 90s, the role of behavioral therapy and the use of highly controlled learning environments emerged as the primary treatments for many forms of autism and related conditions.[2]

Unbeknown to Kanner, at the same time as his theory of ‘infantile autism’ was published in an English-language journal, a German paediatrician called Hans Asperger published a descriptive paper of four boys in a German language journal. They all shared similar characteristics to the descriptions of Kanner’s children, but were functioning at a higher level. They shared some aggression, a high pitched voice, adult-like choice of words, clumsiness, irritated response to affection, vacant gaze, verbal oddities, prodigious ability with arithmetic and abrupt mood swings. Asperger was the first to propose that these traits were the extreme variant of male intelligence[4].

But the full impact of Asperger wasn’t felt until 1981, when British psychiatrist Lorna Wing translated Aspergers original paper into English. By this time, autism had become a disorder of its own according to the DSM-III, the gold-standard reference of psychiatric diagnosis, but it was still largely defined by the trait of profound deficit. Aspergers description of a ‘high-functioning’ form of autism resonated amongst the autism community, and a diagnosis of Aspergers Syndrome became formally recognised in the early 1990’s with the publication of the DSM-IV.

The most recent history of autism comes in two parts. The first was the revision of the DSM-IV. For the first time, rather than two separate diagnoses, Autism and Aspergers have been linked together as a spectrum and collectively known as the Autism Spectrum Disorders (although autism self-advocates prefer the term ‘conditions’ to ‘disorders’).

The second part is a highly controversial chapter that will stain the history of autism research and scientific confidence, into the next few decades. Chris Mooney, in a piece for Discover Magazine, sums it up nicely:

“The decade long vaccine-autism saga began in 1998, when British gastroenterologist Andrew Wakefield and his colleagues published evidence in The Lancet suggesting they had tracked down a shocking cause of autism. Examining the digestive tracts of 12 children with behavioral disorders, nine of them autistic, the researchers found intestinal inflammation, which they pinned on the MMR (measles, mumps, and rubella) vaccine. Wakefield had a specific theory of how the MMR shot could trigger autism: The upset intestines, he conjectured, let toxins loose in the bloodstream, which then traveled to the brain. The vaccine was, in this view, effectively a poison.”[5]

Inflamed by a post-modern distrust of science and a faded memory of what wild-type infectious diseases did to children, the findings swept through the internet and social media and lead to a fall in vaccination rates (from about 95% to below 80% at its lowest)[6].

But the wise words, “Be sure your sins will find you out”, still hold true, even in modern science. In 2010, Wakefield was found guilty of Serious Professional Misconduct by the British General Medical Council, and was struck off the register of medical practitioners in the UK. In the longest ever hearing into such allegations, the GMC considered his conduct surrounding the research project, the medical treatment of his child subjects, and his failure to disclose his various conflicts of interest to be dishonest and professionally and clinically unethical[7]. There is evidence that he also selectively chose his subjects to confound the results, misrepresented the time course of their symptoms related to the vaccinations, misrepresented their diagnosis of autism, and altered the reports of their bowel tests[8, 9].

For the record, this isn’t a comment on the science of Wakefield’s rise and fall, but the history. I am not suggesting that the proposed autism/vaccination link should be discounted solely on the basis of Wakefield’s scientific fraud. Rigorous science has already done that. The science for and against the proposed link between autism and vaccinations deserves special attention, and will be discussed in a future post. Rather, lessons need to be learned from what is one of the most destructive cons in the recent history of medicine.

The losers of this hoax are twofold. Thousands of children have unnecessarily suffered from preventable infectious disease because of a fear of vaccines that has turned out to be unfounded, and those who actually have autism miss out on actual funding because it was syphoned off into Wakefield’s pockets and into research disproving his rancid theory. As the editorial in the BMJ stated, “But perhaps as important as the scare’s effect on infectious disease is the energy, emotion, and money that have been diverted away from efforts to understand the real causes of autism and how to help children and families who live with it.”[6]

As with all good history, there are lessons for the future. Autism is still largely misunderstood. The vacuum of definitive scientific knowledge is slowly being filled, gradually empowering people with autism and the people that interact with them to truly understand and communicate. Each breakthrough and revision of the diagnosis has lead to more sophisticated and more humane ways of living with autism. But there is still a need for caution – people will use the gaps in knowledge and the pervasive distress that can come from the diagnosis, to manipulate and exploit for their own ends.

I’ll continue with the series in the next week or so, looking at the modern “epidemic” of autism.

REFERENCES:

1. Wolff, S., The history of autism. Eur Child Adolesc Psychiatry, 2004. 13(4): 201-8.
2. WebMD: The history of autism. 2013  [cited 2013 August 14]; Available from: http://www.webmd.com/brain/autism/history-of-autism.
3. Kanner, L., Autistic disturbances of affective contact. Acta Paedopsychiatr, 1968. 35(4): 100-36.
4. Draaisma, D., Stereotypes of autism. Philos Trans R Soc Lond B Biol Sci, 2009. 364(1522): 1475-80.
5. Mooney, C., Why Does the Vaccine/Autism Controversy Live On?, in Discover2009, Kalmbach Publishing Co: Waukesha, WI.
6. Godlee, F., et al., Wakefield’s article linking MMR vaccine and autism was fraudulent. BMJ, 2011. 342: c7452.
7. General Medical Council. Andrew Wakefield: determination of serious professional misconduct, 24 May 2010. http://www.gmc-uk.org/Wakefield_SPM_and_SANCTION.pdf_32595267.pdf
8. Deer, B., How the case against the MMR vaccine was fixed. BMJ, 2011. 342: c5347.
9. Deer, B., More secrets of the MMR scare. Who saw the “histological findings”? BMJ, 2011. 343: d7892.