PatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
This is a pervasive developmental disorder. First described by Hans Asperger in 1944, Asperger's syndrome (AS) lies within the autistic spectrum. Previously it was called high-functioning autism. The main difference from classic autism is a lack of delayed or retarded cognition and language. Those with AS are also more likely to seek social interaction and share activities and friendships.
Prevalence is 2-3 per 10,000. This has changed as diagnostic criteria have become more specific. Lorna Wing (who is credited as having first described a 'triad of impairment') began the debate on whether Asperger's syndrome (AS) is a discrete syndrome from autism/autistic spectrum disorders (ASDs). AS primarily occurs in boys, with a fairly consistent ratio of male:female = 8:1.
Autism is a complex disorder with an established genetic basis.
- Chromosome 7q is particularly important, although others are also thought to be involved.
- There is 88% concordance in identical twins. Siblings are more likely to be diagnosed. Twins may be differently affected within the spectrum of disability.
- Environmental factors have been implicated, although there is little conclusive evidence:
- Toxins like lead, antimony and mercury have been found in high levels in the hair and blood samples of affected children. It may be that autistic spectrum disorder (ASD) children are unable to detoxify as efficiently as other children.
- This hypothesis is similar to the premise behind the gluten- and casein-free diet. Peptides produced by gluten and casein act as morphine-like substances to ASD children and exaggerate their behaviours. Currently, however, there is insufficient evidence for improved behaviour with the exclusion diet.
- Measles, mumps and rubella (MMR) vaccine and autism:
- This has been heavily covered in the media. The position of the Medical Research Council is that, "there are no epidemiological studies that provide reliable evidence to support the hypothesis that there might be an association between MMR and ASD". The majority of the original researchers who claimed a link have retracted their interpretations. Wakefield has been widely discredited.
- In the USA, several claims for vaccine injury are currently progressing through the courts.
In classic autism, children tend to be spotted earlier (18-30 months) because of impaired communication. In Asperger's syndrome (AS), the diagnosis comes later - usually at school entry, when socialisation becomes necessary. Many people with AS may learn to mask their problems. They may present as patients with no serious mental health problem, but who are anxious, lonely, have a poor employment record and just don't seem to fit in.
There is normal speech development before the age of four years, with good grammar and vocabulary. However, their tone is flat and they are pedantic. They also have a restricted repertoire of subjects. They have poor non-verbal communication skills. They may take language very literally and be unable to interpret idiom. For example, if you use the phrase 'in a nutshell', they will be confused at how what you are talking about is going to end up inside a nut.
They are often obsessed with complex subjects and described as 'eccentric' or 'little professors'. IQ is normal - above average. They score well in verbal ability but below average in performance abilities. Patients with AS may be highly creative, and have exhibited outstanding skills in mathematics, music, and computer sciences. Their strength lies in concrete, rather than abstract, thinking. They have poor powers of imagination. They lack an intuitive theory of mind (ability to imagine what others are thinking or feeling), and are often unable to talk about their own emotions, which may lead to anxiety and depression in later life. They also lack central coherence. This is the ability to integrate individual elements of perception into an overall context of meaning, ie seeing the "bigger picture". The following statement could be typical of a patient with AS: "I see hundreds of individual trees, but I cannot see a forest." They tend to be detail orientated and have great difficulty understanding the overall context.
There are delayed motor milestones and then clumsiness. There are poor sleep patterns. They experience difficulties falling, and staying, asleep. They are Interested in others more than with autism but do not share interests. Their interaction is nanve and one-sided. They are solitary, with no friends; socially aware - but may display inappropriate reciprocal interaction. They may be seen as eccentric. They are excellent train-spotters and collectors.
Associated medical problems
- 25-30% of children on the autistic spectrum may have seizures. This usually appears in puberty. These are more common in children who have significant cognitive problems or dysmorphic features.
- Visual impairment.
- Hearing impairment.
- Approximately 70% also meet diagnostic criteria for at least one other (often unrecognised) psychiatric disorder, such as depression or attention deficit hyperactivity disorder (ADHD). This may also be impairing their social functioning.
- Intellectual disability (IQ below 70) occurs in approximately 50%.
- Underlying medical conditions, such as untreated phenylketonuria, congenital rubella, cytomegalovirus or toxoplasmosis, fragile X syndrome or tuberous sclerosis.
- Pica (or mouthing) is also commonly seen.
- Sleep disorders (of onset, maintenance and duration) are also common.
There is currently no policy for routine screening in the UK (unlike in the USA). These tools may help with a decision to refer for specialist assessment after a parent has raised concerns about their child. There are several screening questionnaires in use including:
- The CHAT (= CH ecklist for A utism in T oddlers) and its modifications CHAT 23 and M-CHAT.
- Pervasive developmental disorder screening test (PDDST).
- Screening tool for autism in two-year-olds (STAT).
- Social communication questionnaire (SCQ), which is used in school-aged children.
All focus on assessing key characteristics, such as joint attention, social communication and play. A negative result from screening does not rule out the diagnosis. If parental concerns continue, a referral is advisable.
The assessment of children and young people with developmental delay, emotional and behavioural problems, or genetic syndromes should include surveillance for autistic spectrum disorder (ASD) as part of routine practice.
Making the diagnosis
The condition can be reliably diagnosed between 2-3 years of age. The National Institute for Health and Clinical Excellence (NICE) has published guidance for assessment and referral of children with suspected autism:
- Specialist diagnosis is required. This is probably best done by paediatric neurologists, developmental and behavioural paediatricians, child psychiatrists or psychologists. Ideally there should be a multidisciplinary team ('the autism team'), with specific training and experience in evaluating children with autism. Involvement of speech and language and occupational therapists, special educators, and social workers may provide a more detailed assessment of specific domains.
- Other conditions need to be excluded and investigations for chromosome analysis, hearing and sight tests are usually taken prior to reaching the diagnosis. Where clinically relevant, the following should be considered for all children and young people with autistic spectrum disorder (ASD):
- Examination of physical status, with particular attention to neurological and dysmorphic features.
- Karyotyping and fragile X DNA analysis.
- Hearing examination.
- Investigations to rule out recognised causes of ASD, eg tuberous sclerosis.
- Assessments of children and young people for ASD cannot be rushed. It may not be possible to obtain sufficient evidence in one session and the child/young person may require observation in different settings, eg at school (especially in unstructured activity such as break-time) as well as clinic.
- Autistic disorder is diagnosed when an individual exhibits six or more symptoms across the three core areas.
- All children and young people with ASD should have a comprehensive assessment of their speech, language and communication skills. This will help to decide which interventions are best suited for that child.
When to refer
- Children whose language or social skills have regressed.
- If you are concerned about possible autism on the basis of reported or observed signs and symptoms. Even if a screening tool is negative, consider referral if concerns persist.
- If there are risk factors which make autism more likely:
- Factors associated with birth: gestational age ≤35 weeks; birth defects associated with central nervous system malformation, eg cerebral palsy.
- Family: a sibling with autism.
- Parental ill health consequences: schizophrenia-like psychosis; sodium valproate use during pregnancy
- A child's own health problems: intellectual disability; neonatal encephalopathy; chromosomal disorders, eg trisomy; genetic disorders, eg fragile X, muscular dystrophy, neurofibromatosis, tuberous sclerosis.
Management is usually undertaken in educational settings. Local support networks may be in place for educational support in mainstream school if appropriate and will feed down from paediatrician or educational psychologist. Occupational therapy, speech therapy and physiotherapy may help specific problems.
Many educational approaches are commonly used:
- Applied behavioural analysis - Lovaas pioneered a system for teaching skills in bite-sized pieces by using motivators (specific to the child) to reward achievement. It is taught intensively (40 hours per week) in a one-to-one situation. It should be started as early as possible. There are some specialised schools which use this method extensively. They tend to be independent and expensive. Tutors can be contacted to come to the home. See the PEACH (= P arents for the E arly Intervention of A utism in CH ildren) website under 'Internet and further reading', below. There is some evidence in support of this approach, particularly for >30 hours per week. However, the Lovaas programme should not be presented as an intervention that will lead to normal functioning.
- Early start Denver model - this combines applied behavioural analysis with developmental and relationship based approaches. It is aimed at toddlers and uses a developmental curriculum. The principles include bringing the child into interactive social relationships, using positive emotional exchanges, and developing joint play activities to target deficits. It has been shown to improve cognitive performance, language skills and adaptive behaviour skills in some young children with autism. Unfortunately, the research methods are not robust.
- TEACCH method (= T reatment and E ducation of A utistic and C ommunication-related handicapped CH ildren) - this approach emphasises the organisation of the child's physical learning environment. Teachers use predictable sequences of activities. The child is reassured by visual schedules and visually structured activities. There is flexibility built into routines.
Other supportive interventions include:
- Interventions supporting communication, such as the use of visual augmentation, eg pictures of objects. The picture exchange communication system (PECS) is a system of easily recognisable pictures which the child uses to communicate. This may help to reduce frustration and anxiety.
- Speech and language therapy; this is most effective when they train and work with teachers, families and peers promoting functional communication in normal environments.
- Social skills (in joint attention, interactive play, responding to social overtures, and initiating and maintaining social behaviour) can be taught explicitly. When children are school-aged, social skills groups can be useful. Using videos and social stories can help to teach specific skills.
- Occupational therapy focuses on development and maintenance of fine motor and adaptive skills. It can also look at problems of processing and integrating sensory input.
No matter which approach is used, it is recommended that the intervention should be systematically planned and delivered for at least 25 hours a week, consistently. It is also recommended that classrooms should have a high degree of structure and a low student-to-teacher ratio. The child's developmental level should dictate their curriculum.
Behavioural management for parents
Advise parents to join a self-help group. The National Autistic Society (NAS) or parent-school partnerships often run local groups. The NAS run 'Early Bird' courses for parents. This a 12-week programme to help parents try to understand their child's behaviour and begin to cope. Contact: Early Bird Centre 01226 779218 or via email.
There are many strategies available to help parents. All claim good success, although the efficacy is not well-established for any. The major ones will be outlined and there are links if further information is required. Very few are available on the NHS and costs are generally borne by the parents:
- Sensory integration therapy has been used when there are marked sensory perception issues, eg over-sensitivity to touch. Occupational therapists desensitise the child gently over time. Auditory Integration Therapy (AIT) is offered to children on the autistic spectrum because they appear to experience pain when listening to certain sounds. In AIT the child listens to modulated music tapes through headphones for a certain period of time. However, 50% of the studies show no benefit. Therefore AIT is not recommended.
- Irlen lenses: this is when differently coloured lenses are used in glasses or over written matter. They may help with difficulties in visual perception. See 'Internet and further reading', below.
- Evidence from trials is lacking for a gluten-/casein-free diet, although many parents claim excellent results. Luke Jackson wrote an excellent 'user's guide' whilst he was a teenager.
- Risperidone is useful for short-term treatment of significant aggression, tantrums or self-injury in children with autism. There is some evidence of benefits in irritability, repetition and social withdrawal.
- Methylphenidate may be considered for treatment of attention difficulties/hyperactivity in children or young people with ASD, although it tends to be less well tolerated.
- Melatonin may be considered for treatment of sleep problems which have persisted despite behavioural interventions. Meta-analysis has showed significant improvement with minimal side-effects.
Because of their ability to compensate and mask their problems, many with Asperger's syndrome (AS) do find work in mainstream jobs.
Relationships, personal and social, remain difficult. Few marry.
- Some children may improve at 4-6 years of age when they may be able to model normal behaviour from school peers. There is currently a policy of inclusion within the education system which will attempt to support the majority of autistic spectrum disorder (ASD) sufferers within mainstream schools.
- Articulate people with ASD are writing about their experiences (Temple Grandin, Donna Williams), and the public is more knowledgeable and sometimes sympathetic. Adults are living full lives; however, the NAS published a report in 2001 called "Ignored or ineligible? The reality for adults living with Autistic Spectrum Disorders". The results were not positive and showed 49% of adults still living with parents. 12% at the higher-functioning end were in full-time employment.
- Some will need external support and this can be accessed through a community care assessment.
- The NAS publish good practice guidelines for services dealing with adults with ASD.
- "Prospects" is an NAS-supported employment service.
Further reading & references
- Psychiatric services for adolescents and adults with Asperger syndrome and other autistic-spectrum disorders, Royal College of Psychiatrists (2006)
- No Author listed - What are the diagnostic criteria of Asperger's Disorder? DSM-IV Diagnostic criteria for Asperger's Disorder
- National Autistic Society
- Brasic JR, Asperger Syndrome, Medscape, Jul 2011
- Freaks, Geeks and Asperger's Syndrome. Luke Jackson. 2002. London. Jessica Kingsley Publishers Ltd. First-hand account of living with AS by articulate teenager.
- Asperger's Syndrome, a Guide for Parents and Professionals. T Attwood. 1998. London. Jessica Kingsley Publishers Ltd.
- A User Guide to the GF/CF Diet for Autism. Asperger syndrome and AD/HD. Luke Jackson. 2001. London. Jessica Kingsley Publishers Ltd.
- PEACH, Parents for the Early Intervention of Autism in CHildren (Peach), UK parent-led charity established to promote early behavioural intervention for young children with autism, Applied Behavioural Analysis (ABA)
- Fombonne E, Tidmarsh L; Epidemiologic data on Asperger disorder. Child Adolesc Psychiatr Clin N Am. 2003 Jan;12(1):15-21, v-vi.
- Wing L; Asperger's syndrome: a clinical account. Psychol Med. 1981 Feb;11(1):115
- Bonora E, Lamb JA, Barnby G, et al; Mutation screening and association analysis of six candidate genes for autism on chromosome 7q. Eur J Hum Genet. 2005 Feb;13(2):198-207.
- Blenner S, Reddy A, Augustyn M; Diagnosis and management of autism in childhood. BMJ. 2011 Oct 21;343:d6238. doi: 10.1136/bmj.d6238.
- Millward C, Ferriter M, Calver S, et al; Gluten- and casein-free diets for autistic spectrum disorder. Cochrane Database Syst Rev. 2008 Apr 16;(2):CD003498.
- Doja A, Roberts W; Immunizations and autism: a review of the literature. Can J Neurol Sci. 2006 Nov;33(4):341-6.
- Fitzpatrick M; The end of the road for the campaign against MMR. Br J Gen Pract. 2007 Aug;57(541):679.
- Review of Autism and Research: Epidemiology and Causes, London Medical Research Council (MRC), December 2001; review of the MMR debate
- Murch SH, Anthony A, Casson DH, et al; Retraction of an interpretation. Lancet. 2004 Mar 6;363(9411):750.
- Dyer C; Wakefield was dishonest and irresponsible over MMR research, says GMC. BMJ. 2010 Jan 29;340:c593. doi: 10.1136/bmj.c593.
- Stewart AM; When vaccine injury claims go to court. N Engl J Med. 2009 Jun 11;360(24):2498-500.
- Frith U; Emanuel Miller lecture: confusions and controversies about Asperger syndrome. J Child Psychol Psychiatry. 2004 May;45(4):672
- Pickett J, Xiu E, Tuchman R, et al; Mortality in Individuals With Autism, With and Without Epilepsy. J Child Neurol. 2011 Apr 6.
- Tuchman R, Cuccaro M, Alessandri M; Autism and epilepsy: historical perspective. Brain Dev. 2010 Oct;32(9):709-18. Epub 2010 May 26.
- Lugnegard T, Hallerback MU, Gillberg C; Psychiatric comorbidity in young adults with a clinical diagnosis of Asperger Res Dev Disabil. 2011 Apr 23.
- Murray MJ; Attention-deficit/Hyperactivity Disorder in the context of Autism spectrum Curr Psychiatry Rep. 2010 Oct;12(5):382-8.
- Assessment, diagnosis and clinical interventions for children and young people with autism spectrum disorders; Scottish Intercollegiate Guidelines Network - SIGN (2007)
- Autism spectrum disorders in children and young people, NICE Clinical Guideline (September 2011)
- Lovaas OI; Behavioral treatment and normal educational and intellectual functioning in young autistic children. J Consult Clin Psychol. 1987 Feb;55(1):3-9.
- Virues-Ortega J; Applied behavior analytic intervention for autism in early childhood: Clin Psychol Rev. 2010 Jun;30(4):387-99. Epub 2010 Feb 11.
- Sinha Y, Silove N, Wheeler D, et al; Auditory integration training and other sound therapies for autism spectrum Arch Dis Child. 2006 Dec;91(12):1018-22. Epub 2006 Aug 3.
- The Gluten Free/Casein Free Diet: a User's guide by Luke Jackson. London. Jessica Kingsley Publishers. ISBN 1-84310-055-x
- Hazell P; Drug therapy for attention-deficit/hyperactivity disorder-like symptoms in autistic disorder. J Paediatr Child Health. 2007 Jan;43(1-2):19-24.
- Jesner OS, Aref, Coren E; Risperidone for autism spectrum disorder. Cochrane Database Syst Rev. 2007 Jan 24;(1):CD005040.
- Rossignol DA, Frye RE; Melatonin in autism spectrum disorders: a systematic review and meta-analysis. Dev Med Child Neurol. 2011 Apr 19. doi: 10.1111/j.1469-8749.2011.03980.x.
- Thinking In Pictures and Other Reports from My Life with Autism by Temple Grandin. New York. Bantam Doubleday Dell Publishing
- Autism: An Inside-out Approach by Donna Williams. London. Jessica Kingsley Publishers. First hand account of what it's like to live with ASD
- Ignored or ineligible? The reality for adults with autism spectrum disorders, The National Autistic Society, 2001
- Supporting adults with autism: a good practice guide for NHS and local authorities, The National Autistic Society, 2009
- Good practice in supporting adults with autism, The National Autistic Society, 2009
- Prospects, The National Autistic Society
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Hayley Willacy
Dr Hayley Willacy
Dr Helen Huins