Facts and statistics about autism, including how many autistic people are in the UK, how many autistic people have learning disabilities, a breakdown by gender, a history of autism studies, and some common myths and facts about the condition.
How does autism affect children, adults and their families?
The term 'autism' is used here to describe all diagnostic profiles, including Asperger syndrome and Pathological Demand Avoidance (PDA).
- Without understanding, autistic people and families are at risk of being isolated and developing mental health problems.
- Autism is much more common than many people think. There are around 700,000 people on the autism spectrum in the UK – that's more than 1 in 1001. If you include their families, autism touches the lives of 2.8 million people every day.
- Autism doesn't just affect children. Autistic children grow up to be autistic adults.
- Autism is a hidden disability – you can't always tell if someone is autistic.
- While autism is incurable, the right support at the right time can make an enormous difference to people's lives.
- 34% of children on the autism spectrum say that the worst thing about being at school is being picked on2.
- 63% of children on the autism spectrum are not in the kind of school their parents believe would best support them3.
- 17% of autistic children have been suspended from school; 48% of these had been suspended three or more times; 4% had been expelled from one or more schools4.
- Seventy per cent of autistic adults say that they are not getting the help they need from social services. Seventy per cent of autistic adults also told us that with more support they would feel less isolated5.
- At least one in three autistic adults are experiencing severe mental health difficulties due to a lack of support6.
- Only 16% of autistic adults in the UK are in full-time paid employment, and only 32% are in some kind of paid work7.
- Only 10% of autistic adults receive employment support but 53% say they want it8.
1 The NHS Information Centre, Community and Mental Health Team, Brugha, T. et al (2012). Estimating the prevalence of autism spectrum conditions in adults: extending the 2007 Adult Psychiatric Morbidity Survey. Leeds: NHS Information Centre for Health and Social Care
2 Reid, B. (2011). Great Expectations. London: The National Autistic Society, p7
3 Reid, B. (2011). Great Expectations. London: The National Autistic Society, p18
4 Reid, B. (2011). Great Expectations. London: The National Autistic Society, p8
5 Bancroft et al (2012). The Way We Are: Autism in 2012. London: The National Autistic Society
6 Rosenblatt, M (2008). I Exist: the message from adults with autism in England. London: The National Autistic Society, p3
7 The National Autistic Society (2016). The autism employment gap: Too Much Information in the workplace. p5
8 Bancroft et al (2012). The Way We Are: Autism in 2012. London: The National Autistic Society
Around 700,000 people may be autistic, or more than 1 in 100 in the population.
There is no register or exact count kept. Any information about the possible number of people with autism in the community must be based on epidemiological surveys (ie studies of distinct and identifiable populations).
The latest prevalence studies of autism indicate that 1.1% of the population in the UK may have autism. This means that over 695,000 people in the UK may have autism, an estimate derived from the 1.1% prevalence rate applied to the 2011 UK census figures.
The prevalence rate is based on two relatively recent studies, one of children and the other of adults. The prevalence study of children, (Baird G. et al., 2006) looked at a population in the South Thames area. The study of adults was published in two parts, Brugha et al (2009), and The NHS Information Centre, Community and Mental Health Team, Brugha et al (2012). This is the only known prevalence study to have been done of an adult population.
What proportion of people with autism have a learning disability?
Between 44% - 52% of autistic people may have a learning disability.
Between 48% - 56% of autistic people do not have a learning disability.
Research findings on the proportion of people with autism spectrum disorders who also have learning disabilities (IQ less than 70) vary considerably as they are affected by the method of case finding and the sample size.
Fombonne et al (2011), in their research review of 14 prevalence studies that mentioned IQ, found a range of 30% to 85.3%, with a mean of 56.1%, of people without learning disabilities, p. 99.
Emerson and Baines (2010) in their meta-analysis of prevalence studies found a range of people with learning disabilities and autism from 15% to 84%, with a mean of 52.6%.
Explanation of why these findings are so variable and the reliability of the figures can be found in both Emerson and Baines (2010) and in Fombonne et al (2011).
What proportion of people with a learning disability are autistic?
Around a third of people with a learning disability may also be autistic.
Around a third of people who have learning disabilities (IQ less than 70) are also autistic, according to research published by Emerson and Baines in 2010. The adult prevalence study, The NHS Information Centre, Community and Mental Health Team, Brugha et al.(2012), found between 31% and 35.4% of people with a learning disability are autistic.
How many males compared to females are diagnosed with autism?
Five times as many males as females are diagnosed with autism.
The proportion of males as opposed to females diagnosed with autism varies across studies, but always shows a greater proportion of males. Fombonne at al (2011) found a mean of 5.5 males to 1 female in their research review.
Baird et al (2006) found a male to female ratio of 3.3:1 for the whole spectrum in their sample. The Adult Psychiatric Morbidity Survey looked at people in private households, and found a prevalence rate of 1.8% male compared with 0.2% female, (Brugha et al, 2009). However, when they extended the study to include those people with learning disabilities who had been unable to take part in the APMS in 2007 and those in communal residential settings, they found that the rates for females were much closer to those of the males in the population with learning disabilities (The NHS Information Centre, Community and Mental Health Team, Brugha et al, 2012).
Note that autism spectrum disorders are under-diagnosed in females, and therefore the male to female ratio of those who are on the autism spectrum may be closer than is indicated by the figure of 5:1. The under recognition of autism spectrum disorders in females is discussed in Gould and Ashton-Smith (2011).
Read more about gender and autism.
It is more than 50 years since Leo Kanner first described his classic autistic syndrome. Since then, the results of research and clinical work have led to the broadening of the concept of autistic disorders. In consequence, estimates of prevalence have increased considerably. This process has occurred in stages, the start of each of which can be linked to particular studies.
Read our charity's timeline to find out more about the history of The National Autistic Society.
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).
The triad of impairments in children with learning disabilities
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. However, as well as looking at children with Kanner autism, Wing and Gould also identified a larger group of children (about 15 per 10,000) who had impairments of social interaction, communication and imagination (which they referred to as the 'triad' of impairments), together with 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 identified as being within the broader 'autism spectrum'. Thus, the total prevalence rate for the spectrum in all children with special needs in the Camberwell study was found to be 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
There have been a number of other epidemiological studies in different countries examining the prevalence of autism (but not the whole spectrum). These results range from 3.3 to 60.0 per 10,000, possibly due to differences in definitions or case-finding methods (Wing and Potter, 2002).
The studies described above identified autistic disorders in children, the great majority of whom had learning disabilities and special educational needs. However, in 1944, Hans Asperger 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).
In 1993, Stephan Ehlers and Christopher Gillberg published the results of a further study carried out in Gothenburg in which they examined children in mainstream schools in order to find the prevalence of Asperger syndrome and other autistic spectrum disorders 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 impairments. Some of the latter may have fitted Asperger description if more information had been available, but they certainly had disorders within the autistic spectrum. The children who were identified were known by their teachers to be having social and/or educational problems but the nature of their difficulties had not been recognised prior to the study.
For over 30 years, Sula Wolff, in Edinburgh, has studied children of average or high ability who are impaired in their social interaction but who do not have the full picture of the triad of impairments. In her book giving results of her studies (Wolff, 1995), she emphasises that the clinical picture overlaps with Asperger syndrome to a large extent. However, these children represent the most subtle and most able end of the autism spectrum. The majority become independent as adults, many marry and some display exceptional gifts, though retaining the unusual quality of their social interactions.
Why include them in the autism spectrum? As Sula Wolff points out, they 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.
In her discussion of prevalence, Sula Wolff quotes Ehlers and Gillberg's study. She considers that their total figure of 71 per 10,000, includes the children she describes.
Autism spectrum disorders
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 spectrum disorders or 90 in 10,000 (Green et al, 2005). These were not differentiated into autism, Asperger syndrome or any type of autism spectrum disorder.
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 a diagnosis of autism spectrum disorder or were known to child health or speech and language services as having 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 autism spectrum disorders, giving an overall figure of 116 in 10,000 for all autism spectrum disorders (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 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).
There may be another reason why Asperger syndrome was rarely found in the study. ICD-10 diagnostic criteria for Asperger syndrome are such that 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.
Prevalence in adults
The Adult Psychiatric Morbidity Survey is the primary data source for monitoring trends in England’s mental health. In 2007 it included for the first time a measure of autism spectrum disorder and found 1% of the population studied had an ASD, (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 could not have been included in the original study. This included people in residential care settings and those with a more severe learning disability. The study was led by Professor Terry Brugha of the University of Leicester, who also led on autism research for the APMS 2007. Combining its findings with the original APMS, it found that the actual prevalence of autism is approximately 1.1% of the English population, (The NHS Information Centre, Community and Mental Health Team, Brugha, T. et al, 2012).
Recent studies from other countries
The Autism and Developmental Disabilities Monitoring Network in the USA looked at 8 year old children in 14 states in 2008, and found a prevalence rate of autism spectrum disorders 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 ASD 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 ASD cases were in the mainstream school population, and had never been diagnosed before. (Kim et al, 2011).
Researchers comparing findings of prevalence studies from different parts of the world over the past few years have come up with a more conservative median estimate of prevalence 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 to be because of broadening diagnostic criteria, diagnostic switching, service availability and awareness of ASD among professionals and the public, (Elsabbagh M. et al, 2012).
Autism and Developmental Disabilities Monitoring Network Surveillance Year 2008 Principal Investigators (2012) Prevalence of autism spectrum disorders - autism and developmental disabilities monitoring network, 14 sites, United States, 2008. Morbidity and Mortality Weekly Report. Surveillance summaries, 61(3), pp. 1-19. Available to download at http://www.cdc.gov/mmwr/preview/mmwrhtml/ss6103a1.htm [Accessed 15/05/2013]
Baird, G. et al. (2006) Prevalence of disorders of the autism spectrum in a population cohort of children in South Thames: the Special Needs and Autism Project (SNAP). The Lancet, 368 (9531), pp. 210-215.
Blumberg, S. J. et al (2013) Changes in prevalence of parent-reported autism spectrum disorder in school-aged U.S. children: 2007 to 2011–2012. National Health Statistics Reports, No 65. Available to download at http://www.cdc.gov/nchs/data/nhsr/nhsr065.pdf [Accessed 15/05/2013]
Brugha, T. et al (2009) Autism spectrum disorders in adults living in households throughout England: report from the Adult Psychiatric Morbidity Survey, 2007. Leeds: NHS Information Centre for Health and Social Care. Available to download at http://www.hscic.gov.uk/catalogue/PUB01131 [Accessed 10/05/2013]
Ehlers, S. & Gillberg, C. (1993). The epidemiology of Asperger syndrome: a total population study. Journal of Child Psychology and Psychiatry, 34(8), pp. 1327-1350.
Emerson, E. and Baines, S. (2010) The estimated prevalence of autism among adults with learning disabilities in England. Stockton-on-Tees: Improving Health and Lives. Available to download at http://www.improvinghealthandlives.org.uk/projects/autism [Accessed 10/05/2013]
Elsabbagh, M. et al (2012) Global prevalence of autism and other pervasive developmental disorders, Autism Research, 5 (3), pp.160-179. Available to download at http://onlinelibrary.wiley.com/doi/10.1002/aur.239/pdf [Accessed 15/05/2013]
Fombonne, E., Quirke, S. and Hagen, A. (2011). Epidemiology of pervasive developmental disorders. In Amaral D.G., Dawson G. and Geschwind D.H. eds. (2011) Autism spectrum disorders. New York: Oxford University Press, pp. 90 – 111. Available from the NAS Information Centre.
Gillberg, C., Grufman, M., Persson, E. & Themner, U. (1986). Psychiatric disorders in mildly and severely mentally retarded urban children and adolescents: epidemiological aspects. British Journal of Psychiatry, 149, pp. 68-74.
Gould, J. and Ashton-Smith, J. (2011) Missed diagnosis or misdiagnosis? Girls and women on the autism spectrum. Good Autism Practice, 12 (1), pp. 34-41. Available from the NAS Information Centre.
Green, H. et al (2005) Mental health of children and young people in Great Britain, 2004. Basingstoke: Palgrave Macmillan. Available to download at http://www.esds.ac.uk/doc/5269/mrdoc/pdf/5269technicalreport.pdf [Accessed 10/05/2013]
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Although over 700,000 people in the UK are autistic (more than 1 in 100 people), false and often negative perceptions about the condition are commonplace.
This lack of understanding can make it difficult for people on the autism spectrum to have their condition recognised and to access the support they need. Misconceptions can lead to some autistic people feeling isolated and alone. In extreme cases, it can also lead to abuse and bullying.
Autism affects more than 1 in 100 people – fact. Over 700,000 people in UK are autistic, which means that 2.8m people have a relative on the autism spectrum.
People tend to 'grow out' of autism in adulthood – myth. It's a lifelong condition – autistic children become autistic adults.
Autism affects both boys and girls – fact. There is a popular misconception that autism is simply a male condition. This is false.
Some autistic people don't speak – fact. Some autistic people are non-verbal and communicate through other means. However, autism is a spectrum condition, so everyone’s autism is different.
Autism is a mental health problem – myth. Autism is a developmental disability. It’s a difference in how your brain works. Autistic people can have good mental health, or experience mental health problems, just like anyone else.
All autistic people are geniuses – myth. Just under half of all people diagnosed with autism also have a learning disability. Others have an IQ in the average to above average range. 'Savant' abilities like extraordinary memory are rare.
Everyone is a bit autistic – myth. While everyone might recognise some autistic traits or behaviours in people they know, to be diagnosed with autism, a person must consistently display behaviours across all the different areas of the condition. Just having a fondness for routines, a good memory or being shy doesn’t make a person 'a bit autistic'.