Autistic spectrum disorders

Synonym: autism, autistic spectrum condition (ASC)

Autistic spectrum disorder (ASD) is characterised by persistent deficits in the ability to initiate and to sustain reciprocal social interaction and social communication, and by a range of restricted, repetitive and inflexible patterns of behaviour, interests or activities that are clearly atypical or excessive for the individual's age and sociocultural context. Sensory differences may also be a presenting feature¹ .

ASD may occur in association with any level of general intellectual or learning ability and the presentation ranges from subtle problems of understanding and impaired social function to severe disabilities. Impairments in each of the areas relevant to ASD occur along a continuum from minimal to severe² .

The onset of the disorder occurs during the developmental period, typically in early childhood, but symptoms may not become fully manifest until later, when social demands exceed limited capacities. Deficits are sufficiently severe to cause impairment in personal, family, social, educational, occupational or other important areas of functioning and are usually a pervasive feature of the individual's functioning observable in all settings, although they may vary according to social, educational, or other context.

Classification^{3 4 5}

When compared with ICD-10, ICD-11 updates the diagnostic criteria for autism to be more in line the DSM-5. Both classifications include Asperger's syndrome, childhood disintegrative disorder and certain other generalised developmental disorders, within the category of 'Autism'.

With regard to the characteristics of autism, both ICD-11 and DSM-5 include the same two categories:

• Difficulties in interaction and social communication.

• Restricted interests and repetitive behaviours.

Both classifications also point to the importance of examining unusual sensory sensitivities, common among people on the autism spectrum.

However, the ICD-11 and the DSM-5 do vary in a number of ways. For example, ICD-11 provides detailed guidelines for distinguishing between autism with and without an intellectual disability. DSM-5 only states that autism and intellectual disability can occur simultaneously. ICD-11 also includes the loss of previously acquired competences as a characteristic to be taken into account when making a diagnosis.

With regard to autism during childhood, ICD-11 places less emphasis on the type of child play, which may vary depending on the country or culture. Instead, it focuses more on whether children follow or impose strict rules when they play, a behaviour that is a common characteristic among autistic people in all cultures.

Aetiology⁶

ASD is not a single disorder. It is now broadly considered to be a multifactorial disorder resulting from genetic and non-genetic risk factors and their interaction.

• Genetic causes including gene defects and chromosomal anomalies have been found in 10-20% of individuals with ASD. Siblings born in families with an ASD subject have a 50 times greater risk of ASD, with a recurrence rate of 5-8%. The concordance rate reaches up to 82-92% in monozygotic twins, compared with 1-10% in dizygotic twins.

• Genome-wide linkage studies suggested linkages on chromosomes 2q, 7q, 15q, and 16p as the location of susceptibility genes.

• Metabolic errors including phenylketonuria, creatine deficiency syndromes, adenylosuccinate lyase deficiency and metabolic purine disorders account for fewer than 5% of individuals with ASD.

• A correlation between cerebellar developmental patterning gene ENGRAILED 2 and autism has been reported. It is the first genetic allele that contributes to ASD susceptibility in as many as 40% of ASD cases.

• Other genes such as UBE3A locus, GABA system genes and serotonin transporter genes have also been considered as the genetic factors for ASD.

• Various environmental factors may also contribute to ASD, including:

  • Prenatal factors such as advanced parental age, exposure to teratogens (eg, thalidomide, maternal anticonvulsants such as valproic acid and organophosphates), maternal diabetes, and certain viral infections (eg, congenital rubella syndrome, influenza, cytomegalovirus).

  • Perinatal factors such as low birth weight, abnormally short gestation length and birth asphyxia.

  • Postnatal factors such as autoimmune disease, viral infection, hypoxia and mercury toxicity.

Current evidence indicates that there is no harmful association between MMR vaccine and ASD even among children already at higher risk of ASD (ie children with older siblings with ASD)⁷ .

Epidemiology^{2 8}

• A community survey in England in 2007 estimated that about 1% of adults have ASD. The prevalence in children is also around 1%.

• A study in greater Glasgow of children aged 0-6 years reported a prevalence of autism of 11.1 per year per 10,000 children in 2007.

• ASD is more commonly diagnosed in boys than in girls, with a ratio of approximately 4:1, although this varies across the spectrum of ASD.

Risk factors³

Factors associated with an increased prevalence include:

• A sibling with autism.

• Birth defects associated with central nervous system malformation and/or dysfunction, including cerebral palsy.

• Gestational age less than 35 weeks.

• Parental schizophrenia-like psychosis or affective disorder.

• Maternal use of sodium valproate in pregnancy.

• A learning (intellectual) disability.

• Attention deficit hyperactivity disorder (ADHD).

• Neonatal encephalopathy or epileptic encephalopathy, including infantile spasms.

• Chromosomal disorders such as Down's syndrome.

• Genetic disorders such as fragile X.

• Muscular dystrophy.

• Neurofibromatosis.

• Tuberous sclerosis.

Presentation^{2 3}

Symptoms in the core domains of ASD usually emerge between 12 and 24 months. Initial presentations vary, and there is no one behavioural sign that rules an ASD diagnosis in or out. Parents' initial concerns may include language delay, lack of response when the child's name is said, and limited eye contact⁹ .

However ASD can be recognised for the first time at any age, despite the fact that it is a lifelong disorder that starts in early life. Some people will not present until later in life. The possibility of an ASD diagnosis may present in education, social work and employment settings. People may present at any time but particularly at times of change or stress - eg, when moving to university, after the death of a spouse or at times of work or life stress.

Indicators of possible ASD include:

Preschool children (or equivalent mental age)

Spoken language

• Language delay (in babble or words - for example, fewer than ten words by the age of 2 years).

• Regression in or loss of use of speech.

• Spoken language (if present) may include unusual:

  • Non-speech-like vocalisations.

  • Odd or flat intonation.

  • Frequent repetition of set words and phrases ('echolalia').

  • Reference to self by name or 'you' or 'she/he' beyond 3 years.

• Reduced and/or infrequent use of language for communication - for example, use of single words although able to speak in sentences.

Responding to others

• Absent or delayed response to name being called, despite normal hearing.

• Reduced or absent responsive social smiling.

• Reduced or absent responsiveness to other people's facial expressions or feelings.

• Unusually negative response to the requests of others (demand avoidant behaviour).

• Rejection of cuddles initiated by parent or carer, although may initiate cuddles themselves.

Interacting with others

• Reduced or absent awareness of personal space, or unusually intolerant of people entering their personal space.

• Reduced or absent social interest in others, including children of their own age - may reject others; if interested in others, may approach others inappropriately, seeming to be aggressive or disruptive.

• Reduced or absent imitation of others' actions.

• Reduced or absent initiation of social play with others, plays alone.

• Reduced or absent enjoyment of situations that most children like - for example, birthday parties.

• Reduced or absent sharing of enjoyment.

Eye contact, pointing and other gestures

• Reduced or absent use of gestures and facial expressions to communicate (although may place adult's hand on objects).

• Reduced and poorly integrated gestures, facial expressions, body orientation, eye contact (looking at people's eyes when speaking) and speech used in social communication.

• Reduced or absent social use of eye contact, assuming adequate vision.

• Reduced or absent joint attention shown by lack of:

  • Gaze switching.

  • Following a point (looking where the other person points to - may look at hand).

  • Using pointing at or showing objects to share interest.

Ideas and imagination

• Reduced or absent imagination and variety of pretend play.

Unusual or restricted interests and/or rigid and repetitive behaviours

• Repetitive 'stereotypical' movements such as hand flapping, body rocking while standing, spinning, finger flicking.

• Repetitive or stereotyped play - for example, opening and closing doors.

• Over-focused or unusual interests.

• Excessive insistence on following own agenda.

• Extremes of emotional reactivity to change or new situations, insistence on things being 'the same'.

• Overreaction or under-reaction to sensory stimuli - for example, textures, sounds, smells.

• Excessive reaction to taste, smell, texture or appearance of food, or extreme food fads.

Age 5-11 years (or equivalent mental age)

Spoken language
This may be unusual in several ways:

• Very limited use.

• Monotonous tone.

• Repetitive speech, frequent use of stereotyped (learnt) phrases, content dominated by excessive information on topics of own interest.

• Talking 'at' others rather than sharing a two-way conversation.

• Responses to others can seem rude or inappropriate.

Responding to others

• Reduced or absent response to other people's facial expression or feelings.

• Reduced or delayed response to their name being called, despite normal hearing.

• Subtle difficulties in understanding other's intentions; may take things literally and misunderstand sarcasm or metaphor.

• Unusually negative response to the requests of others (demand avoidant behaviour).

Interacting with others

• Reduced or absent awareness of personal space, or unusually intolerant of people entering their personal space.

• Reduced or absent social interest in people, including children of his/her own age - may reject others; if interested in others, may approach others inappropriately, seeming to be aggressive or disruptive.

• Reduced or absent greeting and farewell behaviours.

• Reduced or absent awareness of socially expected behaviour.

• Reduced or absent ability to share in the social play or ideas of others, plays alone.

• Unable to adapt style of communication to social situations - for example, may be overly formal or inappropriately familiar.

• Reduced or absent enjoyment of situations that most children like.

Eye contact, pointing and other gestures

• Reduced and poorly integrated gestures, facial expressions and body orientation, eye contact (looking at people's eyes when speaking) and speech used in social communication.

• Reduced or absent social use of eye contact, assuming adequate vision.

• Reduced or absent joint attention shown by lack of:

  • Gaze switching.

  • Following a point (looking where the other person points to - may look at hand).

  • Using pointing at or showing objects to share interest.

Ideas and imagination

• Reduced or absent flexible imaginative play or creativity, although scenes seen on visual media (for example, television) may be re-enacted.

• Makes comments without awareness of social niceties or hierarchies.

Unusual or restricted interests and/or rigid and repetitive behaviours

• Repetitive 'stereotypical' movements such as hand flapping, body rocking while standing, spinning, finger flicking.

• Play repetitive and orientated towards objects rather than people.

• Over-focused or unusual interests.

• Rigid expectation that other children should adhere to rules of play.

• Excessive insistence on following own agenda.

• Extremes of emotional reactivity that are excessive for the circumstances.

• Strong preferences for familiar routines and things being 'just right'.

• Dislike of change, which often leads to anxiety or other forms of distress (including aggression).

• Overreaction or under-reaction to sensory stimuli - for example, textures, sounds, smells.

• Excessive reaction to taste, smell, texture or appearance of food, or extreme food fads.

Other factors that may support a concern about autism

• Unusual profile of skills or deficits (for example, social or motor co-ordination skills poorly developed, while particular areas of knowledge, reading or vocabulary skills are advanced for chronological or mental age).

• Social and emotional development more immature than other areas of development, excessive trusting (naivety), lack of common sense, less independent than peers.

Secondary school age (or equivalent mental age)

Spoken language
This may be unusual in several ways:

• Very limited use.

• Monotonous tone.

• Repetitive speech, frequent use of stereotyped (learnt) phrases, content dominated by excessive information on topics of own interest.

• Talking 'at' others rather than sharing a two-way conversation.

• Responses to others can seem rude or inappropriate.

Interacting with others

• Reduced or absent awareness of personal space, or unusually intolerant of people entering their personal space.

• Long-standing difficulties in reciprocal social communication and interaction: few close friends or reciprocal relationships.

• Reduced or absent understanding of friendship; often an unsuccessful desire to have friends (although may find it easier with adults or younger children).

• Social isolation and apparent preference for aloneness.

• Reduced or absent greeting and farewell behaviours.

• Lack of awareness and understanding of socially expected behaviour.

• Problems losing at games, turn-taking and understanding 'changing the rules'.

• May appear unaware or uninterested in what other young people of their age are interested in.

• Unable to adapt style of communication to social situations - for example, may be overly formal or inappropriately familiar.

• Subtle difficulties in understanding others' intentions; may take things literally and misunderstand sarcasm or metaphor.

• Makes comments without awareness of social niceties or hierarchies.

• Unusually negative response to the requests of others (demand avoidant behaviour).

Eye contact, pointing and other gestures

• Poorly integrated gestures, facial expressions, body orientation, eye contact (looking at people's eyes when speaking) assuming adequate vision, and spoken language used in social communication.

Ideas and imagination

• History of a lack of flexible social imaginative play and creativity, although scenes seen on visual media (for example, television) may be re-enacted.
  

Unusual or restricted interests and/or rigid and repetitive behaviours

• Repetitive 'stereotypical' movements such as hand flapping, body rocking while standing, spinning, finger flicking.

• Preference for highly specific interests or hobbies.

• A strong adherence to rules or fairness that leads to argument.

• Highly repetitive behaviours or rituals that negatively affect the young person's daily activities.

• Excessive emotional distress at what seems trivial to others - for example, change in routine.

• Dislike of change, which often leads to anxiety or other forms of distress, including aggression.

• Overreaction or under-reaction to sensory stimuli - for example, textures, sounds, smells.

• Excessive reaction to taste, smell, texture or appearance of food and/or extreme food fads.

Other factors that may support a concern about autism

• Unusual profile of skills and deficits (for example, social or motor co-ordination skills poorly developed, while particular areas of knowledge, reading or vocabulary skills are advanced for chronological or mental age).

• Social and emotional development more immature than other areas of development, excessive trusting (naivety), lack of common sense, less independent than peers.

Adults^{10 11}

The diagnosis of ASD in adults is challenging, particularly because ASD can coexist with a number of mental health disorders, such as depression and schizophrenia. The possibility of ASD should be considered when a person has:

• One or more of the following:

  • Persistent difficulties in social interaction.

  • Persistent difficulties in social communication.

  • Stereotypical (rigid and repetitive) behaviours, resistance to change, or restricted interests; and

• One or more of the following:

  • Problems in obtaining or sustaining employment or education.

  • Difficulties in initiating or sustaining social relationships.

  • Previous or current contact with mental health or learning disability services.

  • A history of a neurodevelopmental condition (including learning disabilities and ADHD) or mental disorder.

Associated medical problems

• Epilepsy: estimates of the prevalence of epilepsy in ASD vary widely, with some studies reporting almost 50%¹² .

• Visual impairment; hearing impairment.

• Mental health¹³ :

  • Depression, anxiety and obsessive-compulsive disorder are reported to be particularly common in younger adults with ASD.

  • Studies suggest that 30-84% of adults with ASD might have some form of diagnosable mental illness² .

  • Neurodevelopmental disorders such as ADHD are common in adults with ASD.

  • The prevalence of mental health disorders is increased in those with both severe general learning disability and ASD.

• General learning disability.

• Underlying medical conditions, such as untreated phenylketonuria, congenital rubella, cytomegalovirus or toxoplasmosis, fragile X syndrome or tuberous sclerosis.

• Sleep disorders are common.

Screening tools^{2 9}

Early and intensive interventions and support for children with ASD are associated with better outcomes. However, despite increasing awareness of early signs, the mean age of diagnosis for ASD remains 4-5 years of age. Recognition is growing that some girls present with more subtle signs than boys.

Population screening for ASD is not currently recommended in the UK. False positive or false negative results from inappropriate use of screening tests may delay the correct diagnosis. The decision about the need for referral and further assessment should be made on clinical grounds.

However, ASD-specific assessment tools may be used to supplement the process of clinical history taking - eg, Checklist for Autism in Toddlers (CHAT) for children between 18 and 24 months, the Autism Diagnostic Interview, Revised (ADI-R), the Diagnostic Interview for Social and Communication Disorders (DISCO) and the Developmental, Dimensional and Diagnostic Interview.

The Autism Spectrum Quotient-10 instrument may be used to help identify adults with possible ASD who should be referred for further assessment¹¹ .

A negative result from an assessment does not necessarily 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, psychiatric disorders, impaired mental health or genetic syndromes should include surveillance for ASD as part of routine practice.

Differential diagnosis³

• Neurodevelopmental disorders - eg, specific language delay or disorder, learning (intellectual) disability or global developmental delay.

• Mental health and behavioural disorders - eg, ADHD, mood disorder, anxiety disorder, attachment disorders, conduct disorder, obsessive compulsive disorder, schizophrenia.

• Conditions with developmental regression - eg, Rett syndrome, epileptic encephalopathy, childhood disintegrative disorder (Heller's disease).

• Severe hearing impairment.

• Severe visual impairment.

• Selective mutism.

The diagnosis of ASD may be particularly difficult in⁸ :

• Children with a developmental delay/learning difficulties: the developmental/ intellectual age of the child, and not the chronological age, needs to be considered.

• Children from very deprived backgrounds and those with a history of maltreatment: need to distinguish the features of ASD from behaviours caused by maltreatment or deprivation.

Making the diagnosis³

The condition can be reliably diagnosed between 2-3 years of age. The National Institute for Health and Care Excellence (NICE) has published guidance for assessment and referral of children with suspected ASD:

• 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 ASD team'), with specific training and experience in evaluating children with ASD.

• 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, and 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 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 at the 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.

Referring children and young people to the 'ASD team'³

Early assessment, diagnosis and intervention are very important. Indications for specialist referral for further assessment include:

• Refer children younger than 3 years to the 'ASD team' if there is regression in language or social skills.

• Refer first to a paediatrician or paediatric neurologist (who can refer to the 'ASD team' if necessary) children and young people who are older than 3 years with regression in language, or of any age with regression in motor skills.

• Consider referring children and young people to the 'ASD team' if you are concerned about possible ASD on the basis of reported or observed signs and/or symptoms. Take account of:
  

  • The severity and duration of the signs and/or symptoms.

  • The extent to which the signs and/or symptoms are present across different settings (eg, home and school).

  • The impact of the signs and/or symptoms on the child or young person and on their family.

  • The level of parental or carer concern and, if appropriate, the concerns of the child or young person.

• Factors associated with an increased prevalence of ASD.

• The likelihood of an alternative diagnosis.

Management^{2 14}

Early diagnosis and appropriate intervention, specialised educational programmes and structured support may help a person with ASD to maximise their potential. Care should take into account the physical environment and any negative impact minimised by:

• Providing visual supports - eg, words, pictures or symbols that are meaningful for the child or young person.

• Making reasonable adjustments or adaptations to the amount of personal space given.

• Considering individual sensory sensitivities to lighting, noise levels and the colour of walls and furnishings.

• Arranging to support autistic children and young people and their family and carers during times of increased need, including major life changes such as puberty, starting or changing schools, or the birth of a sibling.

Psychosocial interventions should include play-based strategies with parents, carers and teachers to increase attention, engagement and reciprocal communication. Strategies should include techniques to expand communication, interactive play and social routines.

Parent-mediated interventional programmes should be considered, as they may help families interact with their child, promote development and increase parental satisfaction, empowerment and mental health.

Behavioural and other psychological interventions

Intensive behavioural and developmental programmes aim to improve overall functioning, address specific behavioural difficulties associated with ASD, such as sleep disturbance, and increase positive behaviours such as adaptive skills and initiating social contact with peers.

Early intensive behavioural intervention (EIBI) programmes aim to engage the child with ASD in a structured learning programme that is highly individualised, taking into account the idiosyncratic motivations and specific needs of each child.

Interventions for behaviour that challenges

Anticipate and prevent behaviour that challenges: assess and address factors that may increase the risk including impairments in communication, coexisting physical disorders, coexisting mental health problems such as anxiety or depression, the physical and social environment, changes to routines or personal circumstances, developmental change, exploitation or abuse by others, inadvertent reinforcement of behaviour that challenges, and the absence of predictability and structure.

Offer treatment for physical disorders, or coexisting mental health and behavioural problems, and interventions aimed at changing the environment.

Consider antipsychotic medication when psychosocial or other interventions are insufficient or could not be delivered because of the severity of the behaviour. Antipsychotic medication should be initially prescribed and monitored by a paediatrician or psychiatrist.

Communication interventions

Many of the strategies implemented to support communication are designed and managed by speech and language therapists, working in partnership with parents. Speech and language therapy is most effective when speech and language therapists also train and work with teachers, families and peers promoting functional communication in normal environments.

Interventions to support social communication should be considered. Social skills (attention, interactive play, responding to social overtures and initiating and maintaining social behaviours) can be taught explicitly.

Occupational therapy

• Sensory integration therapy has been used when there are marked sensory perception issues - eg, oversensitivity to touch. Occupational therapists desensitise the child gently over time.

• Occupational therapy also focuses on development and maintenance of fine motor and adaptive skills.

• Occupational therapy can also provide advice and support in adapting environments, activities and routines in daily life.

Other interventions

• Music therapy may help improve skills in social interaction, verbal communication, initiating behaviour and social-emotional reciprocity in the short to medium term.

• Systematic reviews of complementary therapies, acupuncture and animal-assisted interventions reported that evidence for the use of complementary and alternative therapies for individuals with ASD is sparse and no strong conclusions can be drawn.

• Advice on diet and food intake should be sought from a dietician if there are significant food selectivity and dysfunctional feeding behaviour, or restricted diets that may be adversely impacting on growth, or producing physical symptoms of recognised nutritional deficiencies or intolerances.

Interventions for life skills

Offer support in developing coping strategies and accessing community services, including developing skills to access public transport, employment and leisure facilities.

Interventions for coexisting problems

• Offer psychosocial and pharmacological interventions for the management of coexisting mental health or medical problems.

• Consider group or individual cognitive behavioural therapy (CBT) for anxiety if the person has the verbal and cognitive ability to engage in an intervention. Consider adapting the delivery of CBT to include:

  • Emotion recognition training.

  • Greater use of written and visual information and structured worksheets.

  • A more cognitively concrete and structured approach.

  • Simplified cognitive activities - eg, multiple-choice worksheets.

  • Involving a parent or carer - eg involving them in therapy sessions.

  • Maintaining attention by offering regular breaks.

  • Incorporating the child or young person's special interests into therapy if possible.

Interventions for sleep problems

Offer an assessment that identifies the nature of the sleep problem and any underlying factors, such as day and night sleep patterns, and any change to those patterns, whether bedtime is regular, and what the sleep environment is like. Consider the possibility of obstructive sleep apnoea.

Develop a sleep plan to help address the identified sleep problems and to establish a regular night-time sleep pattern. Ask the parents or carers to record the child or young person's sleep and wakefulness throughout the day and night over a two-week period. Use this information to modify the sleep plan if necessary and review the plan regularly until a regular sleep pattern is established.

Do not use a pharmacological intervention to aid sleep unless:

• Sleep problems persist despite following the sleep plan.

• Sleep problems are having a negative impact on the child or young person and their family or carers.

If a pharmacological intervention is needed to aid sleep, consider melatonin and only use it following consultation with a specialist paediatrician or psychiatrist with expertise in the management of autism or paediatric sleep medicine. Use it in conjunction with non-pharmacological interventions.

If the sleep problems continue to impact the child or young person or their parents or carers, consider:

• Referral to a paediatric sleep specialist.
  

• Short breaks and other respite care for one night or more.

Interventions for feeding problems, including restricted diets

• Feeding problems, including restricted diets, can result in nutritional deficiencies that may have serious consequences.

• Assess for any feeding, growth or nutritional problems, including restricted diets. Monitor and refer if needed.

• As part of a full nutritional assessment and monitoring, blood tests to check for nutritional deficiencies may be required.

Transition to adult services

Young people with autism who are receiving treatment and care from child and adolescent mental health services (CAMHS) or child health services should be reassessed at around 14 years to establish the need for continuing treatment into adulthood.

If continuing treatment is necessary, make arrangements for a smooth transition to adult services. The timing of transition may vary locally and individually but should usually be completed by the time the young person is 18 years of age.

Adults

• Psychosocial interventions can be used to target a range of outcomes in adults with ASD, including adaptive behaviours, communication, social skills, employment, quality of life and comorbid mental health difficulties.

• Social programmes involve communication and behavioural elements. Most psychosocial interventions aimed at improving outcomes for adults have been developed for children and young people and there is less evidence about their efficacy in adulthood.

• Psychosocial interventions should be considered for adults with ASD if indicated for managing coexisting conditions. There is insufficient evidence to recommend any specific model of psychosocial intervention. However, a diagnosis of ASD should not prevent anyone from receiving these interventions.

• Therefore, if an individual with ASD experiences a symptom or condition (eg, anxiety) that would usually be treated with CBT or related psychosocial intervention, they should receive the intervention recommended by guidelines for that symptom or condition.

• Interventions to improve emotional literacy, distress tolerance, relaxation skills or general adjustment may considered as first-line interventions.

Pharmacological and dietary interventions

The management of ASD is essentially non-pharmacological. However, certain drugs may be considered for the management of coexisting psychiatric or neurodevelopmental conditions and may occasionally have a short-term adjunctive role in alleviating core symptoms of ASD. Any pharmacological intervention should only be undertaken by doctors with appropriate training in the care of people with ASD.

Do not use the following interventions for the management of core features of autism in children and young people: antipsychotics, antidepressants, anticonvulsants, exclusion diets (such as gluten- or casein-free diets).

Prognosis⁸

The outlook for many people with ASD is now much better than it was 50 years ago, with more affected people able to speak, read, and live in the community rather than in institutions, and some will be largely free from symptoms by adulthood. However, most affected individuals are unable to work full-time or to live independently¹ .

• ASD is a lifelong disorder and has a great impact on the child or young person and their family or carers.

• ASD varies greatly in terms of level of impairments which influence the prognosis. A minority of affected people with lower-level impairment live and work independently in adulthood.

• However, there is evidence that adult outcomes are poor and adult developmental milestones such as work, intimate relationships or independence from parents are often not achieved² .

• The presence or absence of associated intellectual disability, language impairment and additional mental health problems are the most important prognostic factors.

• Unaffected language development and the absence of an associated intellectual disability are associated with a more favourable prognosis.

• The prognosis of ASD can be improved by early diagnosis and assessment, with the provision of support and services in education, health services, social care, and voluntary organisations, and contact with other families with similar experiences.