Autism Spectrum Disorder and its prevalence

What is ASD?

The neurodevelopmental disorder we call Autism was identified separately in 1943 by two Austrian-born psychiatrists, Leo Kanner in Baltimore and Hans Asperger in Vienna. Because the children they treated seemed indifferent to other people, the term Autism was used, from the Greek autos for self. Asperger’s work was little known in the English-speaking world until the 1990s, when the term Asperger’s Syndrome began to be applied to milder forms of Autism, especially in people whose communication abilities were less affected.

Autism is a complex and still mysterious disorder or condition, despite a great deal of research in the past 15 years. There is no single cause and no simple cure and people who live with Autism may have unique clusters of symptoms. For many years, Autism was diagnosed on the basis of behaviours that were observed to be different from those of normal children and psychologists and psychiatrists were responsible for diagnosis and treatment. Now Autism is considered more in the realm of neurologists though many specialist insights are needed to understand its complexities. The roles of nature and nurture, genes and the environment, continue to be debated. Both are probably involved, with affected people having a genetic (or epigenetic) susceptibility that may be triggered by environmental factors.

An explanation of Autism as a whole-body accumulation of symptoms is proposed by the pediatric neurologist Martha Herbert: “Genes and environment interact in the fetus or young child, changing cellular function all over the body, which then affects tissue and metabolism in many vulnerable organs. The interaction of this collection of troubles leads to altered sensory processing and impaired coordination in the brain. A brain with such problems produces the abnormal behaviors that we call autism.” Quoted by Jill Neimark, Discovery Magazine April 2007. Martha Herbert, The Autism Revolution, Harvard, 2012.

Whole-body strategies have been known to reverse Autism in some children when started early. Adults can be helped to cope with pain and agitation when specific symptoms are eased. But adults with the full range of whole-body symptoms continue to live with severe Autism.

In 2013, a new Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) was published, in which most forms of Autism (including Asperger’s) are folded into “Autism Spectrum Disorder” (ASD). The criteria for diagnosis were changed from those in DSM-4 (1994) and its revised version (2000). It is thought that about one fifth of the people being diagnosed with some form of Autism in 2008 would not qualify for ASD from 2013 with the new criteria. But that still means one in every 100 people is on the Autism spectrum.

Why are more people identified with ASD now?


Probably there always were people who combined the symptoms of abnormal social interaction and communication with a strong attachment to their own interests and patterns of behaviour. But in the past such people, if seriously affected, would have been generally grouped in the broad categories of mentally defective, subnormal or mentally ill. Those more mildly affected might have been thought eccentric or loners while a few may have excelled in particular abilities.

Research in the 1960s in various world regions found a constant ratio of 4.5 children in every 10,000 with “classic” Autism as defined by Kanner. This rate grew dramatically from the early 1990s. By 2012, in some regions and localities, even higher rates were found --such as one in every 88 children. By 2014, there is general agreement on a rate of 100 in every 10,000, a 20-fold increase compared with the 1960s.

One factor is the widened definition of Autism. To be identified with “classic” Autism or Kanner syndrome in the 1960s and 1970s, a child had to show clear evidence of communication and social deficits as well as bizarre behaviours. By the end of the 20th century, an ASD diagnosis could depend on a smaller number of criteria. This tendency paralleled the inclusion of people with less severe characteristics and labelled with Asperger Syndrome from the early 1990s as well as people who combine Autism with other conditions. The trend was somewhat reversed in 2013 with the new official definition of “Autism Spectrum Disorder” (ASD).

A second reason is the increased awareness of Autism and ASD among professionals who make diagnoses and those who plan and provide services. This had a ratchet effect. As increasing numbers with ASD demand more services, perception of available services may encourage professionals to diagnose that condition more often, and so on.

Has there been a real increase in Autism in the past 30 years? This raises many other questions about the causes of Autism. Substantial research shows a polygenetic aspect, various genes interacting to predispose some people to ASD. But while some distinctive features, such as deletions or mutations of genes, have been found in the genomes of some individuals with Autism, it has not been possible to identify one or a few genes that are clearly responsible for all or most cases.

The explosion of diagnoses in the past 20 years has moved some to blame a vast array of new environmental conditions and contaminants. It has been suggested that people with ASD may be particularly sensitive, even genetically predisposed, to environmental irritants. They have been compared to “canaries in a coal mine” in giving early warning of environmental hazards that could affect everyone.

Failure to find a common cause for all cases has led to understanding ASD as a complex disorder--not a single condition but a group of several distinct conditions that may present a wide range of broadly similar behaviours in people who are affected. So some people prefer the plural terms “autisms” or “Autism Spectrum Disorders”.

People with ASD vary enormously in the range and severity of their symptoms but may be thought to share some traits which distinguish them from “neurotypical” people. Most are awkward in social communication and interactions. Many, apparently trying to find and impose order in their environments, insist on patterns, rituals and routines that make sense to them. Oliver Sacks has called this a “rage for order”. In some people, such traits may become remarkable abilities and confer an “autism advantage”. From some points of view, people with ASD may be considered on a kind of continuum with neurotypical people at large, ranging from empathizers at one end to systemizers at the other, each with his own gifts and strengths.

Some people with ASD have sometimes been distinguished as “high functioning” if they speak and may also have been diagnosed with Aspergers. However such people may be quite challenged in their social and adaptive skills. On the other hand, people who do not speak have long been assumed to have low intelligence and to be “low-functioning” and incapable of language and literacy. 

Adults as well as children have Autism


Everyone knows there are children with Autism, but adults on the Autism spectrum are often overlooked. Parents of young children have been very effective in speaking up for their families in the past 20 years, so there are now relatively good resources for preschool and school children. Parents of older adults actually diagnosed as children with Autism may have had little encouragement to advocate or hope. Too many of today’s adults with ASD were not diagnosed at all as children. Charities find it easier to appeal to governments, donors and the general public for the needs of youngsters. Now the larger numbers diagnosed as children are aging out of school programs into what can seem a service void.

As far as the research can tell, the same proportions of adults live with ASD as in the child population. Major studies in the United Kingdom since 2006 have found that the prevalence of the symptoms of Autism is the same among adults as among children—at least one in every hundred. But most of those adults had not been formally diagnosed.

Only a tiny proportion of adults with ASD have appropriate supports to lead good and fulfilling lives in their communities. Most suffer from assumptions that they have low intelligence and potential. Too many live restricted lives and have few resources to continue learning.

How many Ontario people live with Autism?


Applying the one-per-cent prevalence to Ontario, there could be more than 135,000 people with the symptoms of Autism Spectrum Disorder.
Using 2011 census data of age-groups, that ratio would mean:

30,500 children and youth from birth to 19 years,
33,125 adults aged 20-39,
38,500 aged 40-59,
21,260 aged 60-79, and
5,178 aged 80 and older.

Based on this rate of prevalence, children and youth make up less than one quarter of the total numbers of people living with ASD in Ontario and there would be over 100,000 adults.

Identifying all those adults is difficult. Large numbers are uncounted and unrecognized because their Autism was never diagnosed in childhood when their symptoms would have been clearer. This is true especially for those over 30 now. As Autism had a very low profile with few services in the past, there was no reason for their families to seek that diagnosis. Professionals and policy-makers may then have classified them as mentally retarded, uneducable or developmentally disabled. It may have seemed futile to try to draw out their abilities.

Some factors may alter the ASD ratio as adults age. Other health conditions may shorten their lives, more than for other adults.  Epilepsy for example affects at least one in three with ASD. People with ASD may also be more vulnerable to accidents and to abuse.

Adults with ASD may have lower standards of general health care than other adults. It is hard for many to make their needs well understood and they are often assumed to be incompetent. They may not really understand that anything is wrong and those who do not speak reliably cannot clearly describe their symptoms.

Before they reach adult years, some children originally diagnosed with Autism may improve their social and other skills to the point where they can fully participate in mainstream education and social events. Their families may decide to conceal the original diagnosis of Autism as they feel it to be a stigma.

Our film is part of a movement to think more positively about people who are different. We have tended to assume that those with Autism, especially if they do not speak, have no abilities or intelligence and even that they wilfully obstruct the efforts of their carers and professionals. We think it is more productive to “presume competence” and assume that a person has intellectual and other abilities and wants to learn and to express his essential self in the world.

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