The history of autism

It has been more than 50 years since Leo Kanner first described his classic autistic syndrome. Since then, the results of research and clinical work have helped us learn more about autism. More and more people are being diagnosed as autistic, although we still have a long way to go in creating a world that works for autistic people.

Read our charity's timeline below to explore the history of autism, meet some of our 'autism pioneers' and find out more about the incredible work they've done.

Timeline

The specific pattern of 'abnormal behaviour' first described by Leo Kanner is also known as 'early infantile autism'. Kanner made no estimate of the possible numbers of people with this condition but he thought that it was rare (Kanner, 1943).
Over 20 years later, Victor Lotter published the first results of an epidemiological study of children with the behaviour pattern described by Kanner in the former county of Middlesex, which gave an overall prevalence rate of 4.5 per 10,000 children (Lotter, 1966).

In 1979 Lorna Wing and Judith Gould examined the prevalence of autism, as defined by Leo Kanner, among children known to have special needs in the former London Borough of Camberwell.
They found a prevalence in those with IQ under 70 of nearly 5 per 10,000 for this syndrome, closely similar to the rate found by Lotter. As well as children with Kanner autism, Wing and Gould also found a larger group of children (about 15 per 10,000) who had difficulties with social interaction, communication and imagination (which they referred to as the 'triad' of impairments), as well as a repetitive stereotyped pattern of activities.
Although these children did not fit into the full picture of early childhood autism (or typical autism) as described by Kanner, they were described as being on the broader 'autism spectrum'. The total prevalence rate for all autistic children with special needs in the Camberwell study was approximately 20 in every 10,000 children (Wing and Gould, 1979). Gillberg et al (1986) in Gothenburg, Sweden, found very similar rates in children with learning disabilities.
Other studies in different countries have also looked into autism and numbers of autistic children (but not the whole spectrum). These results range from 3.3 to 60.0 per 10,000. This could be due to differences in definitions or case-finding methods (Wing and Potter, 2002).

Introduction to Asperger syndrome

In 1944, Hans Asperger (read more about the problematic history of Hans Asperger and the removal of Asperger syndrome as a diagnosis) in Vienna had published an account of children with many similarities to Kanner autism but who had abilities, including grammatical language, in the average or superior range. There are continuing arguments concerning the exact relationship between Asperger and Kanner syndromes but it is beyond dispute that they have in common the triad of impairments of social interaction, communication and imagination and a narrow, repetitive pattern of activities (Wing, 1981; 1991).

1993

Stephan Ehlers and Christopher Gillberg published the results of a further study carried out in Gothenburg. This study examined children in mainstream schools. The aim was to find the prevalence of Asperger syndrome and other autism profiles in children with IQ of 70 or above.
From the numbers of children they identified, they calculated a rate of 36 per 10,000 for those who definitely had Asperger syndrome and another 35 per 10,000 for those with social difficulties. Some of these children may have fitted Asperger description if more information had been available, but they were certainly on the autism spectrum. Teachers of these children had previously recognised social and/or educational differences, but had not been able to find a reason for these differences.

1995

For over 30 years, Sula Wolff, in Edinburgh, studied children of average or high ability who had difficulty with social interaction but who did not fit into the triad of impairments. These children represent the most 'subtle' end of the autism spectrum. The majority become independent as adults, many marry, and some display exceptional gifts.
Why include them in the autism spectrum? As Sula Wolff points out, these children often have a difficult time at school and they need recognition, understanding and acceptance from their parents and teachers. The approach that suits them best is the same as that which is recommended for children with Asperger syndrome and high-functioning autism (as it was then called).
Sula Wolff quotes Ehlers and Gillberg's study. She considers that their total figure of 71 per 10,000, includes the children she describes.

2005

A survey by the Office of National Statistics of the mental health of children and young people in Great Britain found a prevalence rate of 0.9% for autism or 90 in 10,000 (Green et al, 2005). These were not separated into autism, Asperger syndrome or other profiles on the autism spectrum.

2006

Gillian Baird and her colleagues published a report of a prevalence study which surveyed a population of children aged 9-10 years in the South Thames region.
All children who either already had an autism diagnosis or had social and communication difficulties were selected for screening.
Children considered to be at risk of being an undetected case because they had a statement of special educational needs were also selected.
Diagnoses were based on ICD-10 criteria. The results showed a prevalence rate of 38.9 in 10,000 for 'childhood autism', and 77.2 in 10,000 for other conditions on the autism spectrum, giving an overall figure of 116 in 10,000 (Baird et al, 2006).
In this study very few children were identified with Asperger syndrome. The authors acknowledged that some children in mainstream schools who did not have a statement of special educational needs would have been missed, because of the selection criteria. The authors note that the prevalence estimate found should be regarded as a minimum figure (Baird et al. 2006).
ICD-10 diagnostic criteria for Asperger syndrome suggests a person who would be diagnosed with Asperger syndrome using the criteria used by Gillberg, would probably receive a diagnosis of childhood autism or atypical autism using the ICD-10 criteria.

The Adult Psychiatric Morbidity Survey is the primary data source for monitoring trends in England’s mental health. In 2007 it included autism for the first time, and found 1% of the population studied were autistic (Brugha, T. et al , 2009).
The Department of Health then funded a project to build on the APMS study and look more closely at the numbers of autistic adults that were not included in the original study. This included people in residential care settings and those with complex needs. Professor Terry Brugha of the University of Leicester led this study. Brugha also led on autism research for the APMS 2007. Combining its findings with the original APMS, the study found that approximately 1.1% of people in England are autistic (The NHS Information Centre, Community and Mental Health Team, Brugha, T. et al, 2012).

The Autism and Developmental Disabilities Monitoring Network in the USA looked at eight-year-old children in 14 states in 2008, and found a prevalence rate of autism within those states overall of 1 in 88, with around five times as many boys as girls diagnosed (Autism and Developmental Disabilities Monitoring Network Surveillance Year 2008 Principal Investigators, 2012).
The National Center for Health Statistics in the USA published findings from telephone surveys of parents of children aged 6-17 undertaken in 2011-12. The report showed a prevalence rate for autism of 1 in 50, (Blumberg, S .J. et al, 2013).
A study of a 0-17 year olds resident in Stockholm between 2001-2007 found a prevalence rate of 11.5 in 1,000, very similar to the rate found other prevalence studies in Western Europe, (Idring et al , 2012).
A much higher prevalence rate of 2.64% was found in a study done in South Korea, where the researchers found two thirds of the people on the autism spectrum were in the mainstream school population, and had never been diagnosed before. (Kim et al, 2011).
Researchers comparing studies from different parts of the world over the past few years have come up with a more conservative estimate of 62 in 10,000. They conclude that the both the increase in estimates over time and the variability between countries and regions are likely thanks to broadening diagnostic criteria, service availability and increasing awareness of autism among professionals and the public, (Elsabbagh M. et al, 2012).