Autism spectrum disorder


Autism spectrum disorder

Autism spectrum disorder (ASD) is a condition that affects social interaction, communication, interests and behaviour. It includes Asperger syndrome and childhood autism.

Some people also use the term autism spectrum condition or ‘neurodiverse’ (as opposed to people without autism being ‘neurotypical’).

The main features of ASD typically start to develop in childhood, although the impact of these may not be apparent until there is a significant change in the person’s life, such as a change of school.

In the UK, it's estimated that about one in every 100 people has ASD.

There is no 'cure' for ASD, but a wide range of treatments – including education and behaviour support – can help people with the condition.

Signs and symptoms

ASD can cause a wide range of symptoms, which are often grouped into two main categories:

Problems with social interaction and communication – including problems understanding and being aware of other people's emotions and feelings; it can also include delayed language development and an inability to start conversations or take part in them properly.

Restricted and repetitive patterns of thought, interests and physical behaviours – including making repetitive physical movements, such as hand tapping or twisting, and becoming upset if these set routines are disrupted.

Children, young people and adults with ASD are often also affected by other mental health conditions such as attention deficit hyperactivity disorder (ADHD), anxiety or depression.

About half of those with ASD also have varying levels of learning difficulties. However, with appropriate support many people can be helped to become independent.

Children with more severe symptoms and learning difficulties are likely to need more additional care and assistance to live independently as adults, although there is no reason why they and their families cannot enjoy a good quality of life.

Getting a diagnosis

Autism features can often be recognised in children before the age of two or three years. However for many, the signs will often only become more noticeable as they get older.

See your GP or health visitor if you notice any of the symptoms of ASD, or if you’re concerned about your child’s development. You can discuss your concerns together in depth before deciding whether your child should be referred for specialist assessment. It can also be helpful to discuss your concerns with your child’s nursery or school.

Adults can also be diagnosed with ASD. See your GP if you are concerned. They may use a screening tool to check if you have signs of ASD and they can refer you to appropriate services in your area.

What causes ASD?

The exact cause of ASD is unknown, but it is thought that several complex genetic and environmental factors are involved. In some cases, an underlying condition may contribute to ASD.

In the past, some people believed that the MMR (mumps, measles and rubella) vaccine caused ASD, but this has been investigated extensively in a number of major studies around the world, involving millions of children, and researchers have found no evidence of a link between MMR and ASD.


Autism in adults

Some people with ASD had features of the condition as a child, but enter adulthood without ever being diagnosed. However, getting a diagnosis as an adult can often help people with ASD and their families understand the condition and work out what kind of support they need.

A number of autism-specific services are available to help adults with ASD find advice and support, get involved in leisure activities and find somewhere they are comfortable.

Some adults with ASD may have difficulty finding a job because of the social demands and changes in routine that working involves. However, they can get support to help them find a job that matches their abilities and skills.

Symptoms of autism spectrum disorder 

Autism spectrum disorder (ASD) can cause a wide range of symptoms, and there are many different ways those symptoms can be grouped.

It is useful for parents to know the signs and symptoms of autism and Asperger syndrome that are related to their child’s stages of development.

See your GP if you notice any of the symptoms of ASD or if you’re concerned about your child’s development. You can discuss your concerns together in depth before deciding whether your child should be referred for a specialist assessment.

Signs of ASD in pre-school children

The features of ASD that often develop in pre-school children are explained below.

Spoken language

delayed speech development (for example, not speaking at least 10 different words by the age of two), or not speaking at all

frequent repetition of set words and phrases

speech that sounds very monotonous or flat

preferring to communicate using single words, despite being able to speak in sentences

Responding to others

not responding to their name being called, despite having normal hearing

rejecting cuddles initiated by a parent or carer (although they may initiate cuddles themselves)

reacting unusually negatively when asked to do something by someone else


Interacting with others

not being aware of other people’s personal space, or being unusually intolerant of people entering their own personal space

little interest in interacting with other people, including children of a similar age

not enjoying situations that most children their age like, such as birthday parties

preferring to play alone, rather than asking others to play with them

rarely using gestures (such as pointing) or facial expressions when communicating

avoiding eye contact



having repetitive movements such as flapping their hands, rocking back and forth or flicking their fingers

playing with toys in a repetitive and unimaginative way, such as lining blocks up in order of size or colour, rather than using them to build something

preferring to have a familiar routine, and getting extremely upset if there are changes to their normal routine

having a strong like or dislike of certain foods, based on the texture or colour of the food as much as the taste


Signs and symptoms of ASD in school-age children

Features of ASD that can develop in older children and teenagers are explained below.

Spoken language

preferring to avoid using spoken language

speech that sounds very monotonous or flat

speaking in pre-learned phrases, rather than putting together individual words to form new sentences

seeming to talk ‘at’ people, rather than sharing a two-way conversation


Responding to others

taking people’s speech literally and being unable to understand sarcasm, metaphors or figures of speech

reacting unusually negatively when asked to do something by someone else


Interacting with others

not being aware of other people’s personal space, or being unusually intolerant of people entering their own personal space

little interest in interacting with other people, including children of a similar age, or having few close friends despite attempts to form friendships

not understanding how people normally interact socially, such as greeting people or wishing them farewell

being unable to adapt the tone and content of their speech to different social situations, for example speaking very formally at a party and then speaking to total strangers in a familiar way

not enjoying situations and activities that most children their age like

rarely using gestures or facial expressions when communicating

avoiding eye contact



having repetitive movements such as flapping their fingers, rocking back and forth or flicking their fingers

playing in a repetitive and unimaginative way, often preferring to play with objects rather than people

developing a highly specific interest in a particular subject or activity

preferring to have a familiar routine, and getting extremely upset if there are changes to their normal routine

having a strong like or dislike of certain foods, based on the texture or colour of the food as much as the taste 


Causes of autism spectrum disorder 

The exact causes of autism spectrum disorder (ASD) are unknown, although it is thought that several complex genetic and environmental factors are involved.

The causes of ASD can be described in two ways:

Primary ASD (also known as idiopathic ASD) – where no underlying factors can be identified to explain why ASD has developed.

Secondary ASD – where an underlying medical condition or environmental factor thought to increase the risk of ASD is identified.

About 90% of cases of ASD are primary, and about 10% are secondary.

Risk factors

Factors thought to increase the risk of developing ASD, known as ‘risk factors’, can usually be divided into five main categories:

Genetic factors – certain genetic mutations may make a child more likely to develop ASD.

Environmental factors – during pregnancy, a child may be exposed to certain environmental factors that could increase the risk of developing ASD.

Psychological factors – people with ASD may think in certain ways that contribute towards their symptoms.

Neurological factors – specific problems with the development of the brain and nervous system could contribute to the symptoms of ASD.

Other health conditions – certain health conditions associated with higher rates of ASD.

Each of these factors is described in more detail below.

Genetic factors

Most researchers believe that certain genes a child inherits from their parents could make them more vulnerable to developing ASD.

Cases of ASD have been known to run in families. For example, younger siblings of children with ASD have an increased risk of developing the condition themselves and it is common for identical twins to both develop ASD.

At present, however, no specific genes linked to ASD have been identified and there are currently no tests that can screen for 'ASD genes'. However, the specialist seeing your child may screen them for genetic conditions that have similar features to ASD, depending on any additional symptoms your child has.

Environmental factors

Some researchers have argued that ASD is not primarily caused by genes, but also by environmental factors. The theory is that a person is born with a vulnerability to ASD, but the condition develops only if that person is exposed to a specific environmental trigger.

Some suggested environmental factors include being born before 35 weeks of pregnancy (premature birth) and exposure to alcohol or medications such as sodium valproate (a medication sometimes used to treat epilepsy) during pregnancy.

No conclusive evidence has been found linking pollution or maternal infections in pregnancy with an increased risk of ASD.

Psychological factors

Much of the research into the possible psychological factors behind ASD is based on a concept known as 'theory of mind' (TOM). This is a person's ability to understand other people's mental states, recognising that each person they meet has their own set of intentions, beliefs, emotions, likes and dislikes. To put it simply, it's seeing the world through another person's eyes.

It is thought that most children without ASD have a full understanding of theory of mind by around the age of four. Children with ASD develop a limited understanding or no understanding at all of theory of mind.

This may be one of the root causes of their problems with social interaction and may explain some of the psychological features of ASD, such as a tendency towards needing an order or routine and getting lost in detail rather than seeing the bigger picture.

Neurological factors

In people without conditions affecting the brain and nervous system (see below), medical theories and brain imaging studies carried out in people with ASD suggest that the connections between parts of the brain called the cerebral cortex, the amygdala and the limbic system may have become scrambled or ‘over connected’.

As a result, people with ASD may suddenly experience an extreme emotional response when seeing a trivial object or event. This may be a reason why people with ASD are fond of routines, as they have found a set pattern of behaviour that does not provoke an extreme emotional response. It may also explain why they often become very upset if that routine is suddenly broken.

This confusion of emotional responses may also explain why children with ASD are interested in topics that most children would find boring, such as train timetables or have altered or exaggerated responses to sensory stimulation such as tastes, sounds, noises, smells.

Other health conditions

Some conditions that are known to increase the risk of ASD include:

Fragile X syndrome – an uncommon genetic condition that usually causes certain facial and bodily characteristics, such as a long face, large ears and flexible joints. 

Tuberous sclerosis – a rare genetic condition that causes multiple non-cancerous tumours to grow throughout the body, including the brain.

Rett syndrome – a rare genetic condition that mostly affects girls. It causes symptoms of ASDs, and difficulties with physical movement and development.

Neurofibromatosis – a number of genetic conditions that cause tumours to grow along your nerves. The main types areneurofibromatosis type 1 and neurofibromatosis type 2.

Muscular dystrophy – a group of inherited genetic conditions that gradually cause the muscles to weaken, leading to an increasing level of physical disability.

Down’s syndrome – a genetic condition that typically causes some level of learning disability and a characteristic range of physical features.

Cerebral palsy – conditions that affect the brain and nervous system, causing problems with a child's movement and coordination.

Infantile spasms – a type of epilepsy that develops while a child is still very young (usually before they are one year old).

Intellectual disability – about half of those diagnosed with autism have an IQ below 70 (the average IQ is 100).


Diagnosing autism spectrum disorder 

In most cases, parents notice the symptoms of autism spectrum disorder (ASD) when their child is around two or three years old.

In some instances, mild cases may not be detected until adulthood.

Diagnosing ASD in children

If you are worried about your child's development, visit your GP. If appropriate, they can refer you to a health professional or team who may specialise in diagnosing ASD, or someone who has access to such a team. They will make a more in-depth assessment.

This health professional may be:

a psychologist – a health professional with a psychology degree, plus further training and qualifications in psychology

a psychiatrist – a medically qualified doctor with further training in psychiatry

a paediatrician – a doctor who specialises in treating children

a speech and language therapist – a specialist in recognising and treating communication problems

Some local health authorities now use multidisciplinary teams. These are made up of a combination of professionals who work together to make an assessment.


There are no individual tests to confirm a diagnosis of ASD, a diagnosis is instead based on the range of features your child is showing.

The type of assessment carried out often depends on things such as access to additional information (for example nursery or school records) and the skills of the professional or team seeing your child.

A detailed assessment for ASD may or may not be required. If one is carried out, this will involve a number of steps, which are explained below.

For most children:

Any existing information about your child's development, health and behaviour may be sought from relevant people, such as your GP, nursery or school staff.

A detailed physical examination will be carried out to rule out possible physical causes of your child's symptoms, and some children may be referred for further tests, such as testing their blood for genetic conditions with similar features to ASD.

In addition, for some children:

You may be asked to attend a series of interviews so a detailed family history and the history of your child's development can be drawn up.

Your child may be asked to attend a series of appointments so that specific skills and activities can be observed and assessed. This is known as a focused observation. Focused observation looks at language, behaviour, the pattern of your child's thinking (known as their cognitive ability) and how they interact with others.

Once this process is complete, a diagnosis of ASD may be confirmed. If a diagnosis of ASD is not confirmed during an assessment, but your child later develops more significant signs of the condition, a re-assessment may be carried out.

After diagnosis

Parents may react in different ways when ASD has been confirmed. Some parents feel relieved because they now understand the reasons behind their child's behaviour and can begin to treat them.

Other parents feel an immense sense of shock and disbelief, as they are naturally worried about what the diagnosis means for their child's future.

However, the diagnosis offers an insight into your child's individuality and personality. In turn, it gives you a chance to guide their development and growth.

When a child is diagnosed with ASD, many parents are keen to find out as much as they can about the condition. The National Autistic Societyhas an excellent range of resources and advice on its website.

You can also the read the National Institute for Health and Care Excellence (NICE) guidelines on diagnosing autism in children and young people and managing autism in children and young people.

Diagnosis of ASD in adults

Some people with ASD grow up without their condition being recognised. But it's never too late to get a diagnosis. Some people may be scared of being diagnosed because they feel it will 'label' them and lower other people's expectations of them. But there are several advantages.

Getting a diagnosis of ASD will help people with the condition and their families understand ASD and decide what sort of support they need. A diagnosis may also make it easier to access autism-specific services and claim benefits.

See your GP if you think you may have ASD and ask them to refer you to a psychiatrist or clinical psychologist. The National Autistic Society website has information on the process of being diagnosed with ASD for adults.


Treating autism spectrum disorder 

There is currently no 'cure' for autism spectrum disorder (ASD). However, a range of specialist education and behavioural programmes (often referred to as interventions) can be effective in improving the skills of children with ASD.

There are many different types of intervention for ASD and it can be hard to judge which one will work best for your child as each person with ASD is affected differently.

Some types of intervention can involve hours of intensive work, and this is not always possible for many families because of the practical, emotional and financial commitments necessary.

The National Autism Society website has information on the many different approaches, therapies and interventions available for ASD.

Any intervention should focus on important aspects of your child's development. These are:

communication skills – such as the ability to start conversations

social interaction skills – such as the ability to understand other people's feelings and respond to them

cognitive skills – such as encouraging imaginative play

academic skills – the ‘traditional’ skills a child needs to progress with their education, such as reading, writing and maths

Treatment for ASD often involves a team of different specialists working together, such as a paediatrician, a psychologist, a psychiatrist, a speech and language therapist and an occupational therapist.

Some of the main treatments used for ASD are explained below.

Social-communication programmes

Your child may be offered a type of programme called a 'social-communication intervention'. This aims to help them communicate and interact with people and make social situations easier.

Depending on your child's age, these programmes may take place at school, or with a parent, carer or teacher.


Applied behaviour analysis (ABA)

Applied behaviour analysis (ABA) involves breaking down skills (such as communication and cognitive skills) into small tasks and teaching those tasks in a highly structured way, as well as rewarding and reinforcing positive behaviour while discouraging inappropriate behaviour.

ABA sessions are normally carried out at home, although some programmes can be integrated into schools or nurseries.

An ABA programme usually begins with simple tasks that become more complex over time, which can help your child's development by gradually improving their skills.

There are concerns from some health professionals about the intensity of certain ABA-based programmes and some professionals feel it is not always clear how useful the skills gained are outside of some highly structured programmes. However, there is good evidence to suggest early intervention programmes that integrate with education can be beneficial.



TEACCH (Treatment and Education of Autistic and Related Communication Handicapped Children) is a type of educational intervention that places great emphasis on structured learning by using visual prompts. This is because research has found that children with ASD often respond better to information that is presented visually.

TEACCH is often delivered at special day centres, but you can also have training so you can continue the intervention activities at home.

Parent education and training

The parents of a child with ASD play a crucial role in supporting their child and helping them improve their skills.

If your child is diagnosed with ASD, it can be useful to find out as much as you can about life with the condition. The National Autistic Society has an excellent range of resources and advice about living with autismon its website.

Communication advice for parents

Communication is a particular challenge for children with ASD. Helping your child communicate can lead to reduced anxiety and improved behaviour.

You may find the following tips useful when communicating and interacting with your child:

use your child’s name so they know you are addressing them

keep background noise to a minimum

keep language simple

speak slowly and clearly with pauses between words

accompany what you say with simple gestures

allow extra time for your child to process what you have said 


Parent support programmes

For more in-depth advice, there are some programmes specifically designed to help parents of children recently diagnosed with ASD, such as the EarlyBird programme provided by the National Autism Society.

This is a free three-month course for families with a child who has been diagnosed with ASD but has not yet started school.

The programme aims to support and inform parents, as well as offering practical advice about looking after a child with ASD and helping to improve their skills.

EarlyBird is offered in most areas of the UK by licensed teams. To find out if there is a team in your area you can call 01226 779218, emailearlybird@nas.org.uk, or check for EarlyBird licensed teams on the National Autistic Society website.

Improving communication skills

As well as the social-communication interventions mentioned above, a number of other treatments may be offered to specifically help overcome communication difficulties your child may have. Some of the main treatments used are described below.

Speech and language therapy

Speech and language therapy (SLT) is a type of skills training designed to improve your child's language skills. This can improve their ability to interact with others socially.

The therapist uses a number of techniques, such as visual aids, stories and toys to improve communication skills. Watch a video about speech and language therapy for more information.

Picture Exchange Communication System (PECS)

Some children with ASD find picture symbols helpful in allowing them to communicate more effectively, which is why an approach called the Picture Exchange Communication System (PECS) is sometimes carried out by trained specialists to help children with the condition.

PECS teaches children to communicate with adults by giving them cards with pictures on them. Over time, the child is taught progressively more difficult skills, such as using pictures to make whole sentences. This approach aims to eventually help children learn to initiate communication with others without prompting.


Makaton is a communication programme that involves using signs and symbols in support of spoken language to help people with ASD communicate with others.

The signs used in Makaton are based on British Sign Language and each sign has a corresponding symbol. These symbols are simple drawings that can often be used independently of the signs. These signs or symbols can be used with speech to help provide extra clues as to what someone is saying.

Over time, as their speech and language skills develop, many people with ASD will stop using the signs or symbols naturally at their own pace and start to rely more on their speech to communicate.

Makaton can be helpful in improving basic communication in some people with ASD, as well as helping to improve social interaction and the ability to build relationships.

Psychological therapy

If your child has ASD and a mental health problem (such as anxiety), or if their behaviour is causing problems, a psychological treatment may be offered.

Psychological treatments, such as cognitive behavioural therapy (CBT), involve meeting with a therapist to talk about feelings and thoughts and how these affect behaviour and wellbeing.

If a treatment like CBT is offered, the professionals involved in the treatment should also be aware of any changes that need to be made to the treatment because of the ASD. This might include more written or visual information (for example, worksheets and images), and using plain English.


No medication is available to treat the core symptoms of ASD, but medication may be able to treat some of the related symptoms or conditions, such as:

problems sleeping – which may be treated with a medication such as melatonin

depression – which may be treated with a type of medication called a selective serotonin reuptake inhibitor (SSRI)

epilepsy – which may be treated with a type of medication called an anticonvulsant

attention deficit hyperactivity disorder (ADHD) – which may be treated with a medication such as methylphenidate

aggressive and challenging behaviour, such as tantrums or self-harming – which may be treated with a type of medication called an antipsychotic if the behaviour is severe, or if psychological treatments (see above) have not helped

However, these medications can have significant side effects and are usually only prescribed by a doctor specialising in the condition being treated. If medication is offered, your child will usually have a check-up after a few weeks to see if it is helping.

Treatments not recommended

A number of alternative treatments have been suggested as potential treatments for ASD.

However, these should be avoided because there is little or no evidence that any of these approaches are effective, and some may even be potentially dangerous.

Some of the treatments not recommended for ASD include:

special diets – such as gluten-free or casein-free diets

neurofeedback – where brain activity is monitored (usually with electrodes placed on the head) and the person being treated can see their brain activity on a screen and is taught how to change it

auditory integration training – a therapy that involves listening to music that varies in tone, pitch and volume

chelation therapy – which uses medication or other agents to remove metal (in particular mercury) from the body

hyperbaric oxygen therapy – treatment with oxygen in a pressurised chamber

facilitated communication – where a therapist or other person supports and guides a person's hand or arm while using a device such as a computer keyboard or mouse


Adults living with autism 

Some people with autism spectrum disorder (ASD) grow up without their condition being recognised, sometimes through choice.

However, a diagnosis can make it easier to access a range of support services that may be available locally.

Treatment and support

With a proper diagnosis, adults with ASD may be able to access local autism support services, if these are available in their area. You can search for services for adults using the Autism Services Directory.

The health professionals who diagnosed you with ASD can usually offer more information and advice about the care and support services available to you.

Examples of programmes that may be available in your local area include:

social learning programmes to help you cope in social situations

leisure activity programmes, which involve taking part in leisure activities (such as games, exercise, and going to the cinema or theatre), usually with a group of other people

skills for daily living programmes to help you if you have problems carrying out daily activities, such as eating and washing

Adults with ASD may also benefit from some of the treatments offered to children with ASD, such as psychological therapy and medication. 


Adults diagnosed with ASD can also claim some benefits, such asPersonal Independence Payment (PIP). This is the new benefit that is replacing Disability Living Allowance (DLA) for people with a disability aged 16 to 64.



Adults with ASD can live in all types of housing. Some people may be suited to a residential care home, while others may prefer to live on their own and receive home support. Others live completely independently.

Supported living can work very well for some adults with ASD as it means they can choose a place to live in the community, they can live alone or with other people, and they can get the support they need. They may need 24-hour care, or they may only need help with important tasks for a couple of hours each week.

The level of support an adult with ASD needs is decided after your local authority's social services make an assessment and it is agreed with the person and their carer.


It can be difficult for people with ASD to find a job. For example, they may find the work environment too noisy, or travelling to work too stressful because of the crowds. Sudden changes in routine can also be upsetting.

However, in the right job and with the right support, people with ASD have much to offer. They are often accurate, reliable and have a good eye for detail. Being in a working environment can help the individual's personal development tremendously.

If you are having problems getting a job or staying in a job, you may be able to access a supported employment programme in your local area. These are programmes that can help you write your CV and job applications, and prepare for interviews.

These programmes can also help you to choose which jobs would suit you and provide training for that role.

Those providing the programme can also advise employers about any changes that need to be made to the workplace to suit people with autism, and support you and the employer before and after you have started work.