What is autism?

Autism spectrum disorder (ASD), or autism, is a complex developmental condition. It is a lifelong condition for which there is no ‘cure’. However, the earlier someone is diagnosed the sooner they are able to access support and services in education, health and social care, a route into voluntary organisations and contact with other children and families with similar experiences. All of these can improve the lives of the child or young person and their family and/or carers.

It is important to know that autism is a spectrum disorder meaning that every autistic person is different and unique. There is an expression which captures this – ‘If you have seen one person with autism, you have seen one person with autism.’ Some autistic people need little, or no support, while others may need help from a parent or carer every day. Like everyone, autistic people have things they are good at as well as things they struggle with.

There are, however, two key difficulties that autistic people share, and which are required for a diagnosis.¹

1. SOCIAL COMMUNICATION AND SOCIAL INTERACTION CHALLENGES

Social communication

Autistic people have difficulties with interpreting both verbal and non-verbal language like gestures or tone of voice. Some autistic people are unable to speak or have limited speech while other autistic people have very good language skills but struggle to understand things like sarcasm or tone of voice. Other challenges include:

• taking things literally and not understanding abstract concepts
• needing extra time to process information or answer questions
• repeating what others say to them (this is called echolalia)

Social interaction

Autistic people often have difficulty ‘reading’ other people – recognising or understanding others’ feelings and intentions and also expressing their own emotions. This can make it very hard to navigate the social world.

Autistic people may:

• appear to be insensitive
• seek out time alone when ‘overloaded’ by other people
• not seek comfort from other people
• appear to behave ‘strangely’ or in a way thought to be socially inappropriate
• find it hard to form friendships.

2. Restricted, repetitive patterns of behaviour, interests or activities

Restrictive and repetitive behaviours

With its unwritten rules, the world can seem a very unpredictable and confusing place to autistic people. This is why they often prefer to have routines so that they know what is going to happen. They may want to travel the same way to and from school or work, wear the same clothes or eat exactly the same food for breakfast for example.

Autistic people may also repeat movements such as hand flapping, rocking or the repetitive use of an object such as twirling a pen or opening and closing a door. Autistic people often engage in these behaviours to help calm themselves when they are stressed or anxious, but many autistic people do it because they find it enjoyable.

Change to routine can also be very distressing for autistic people and make them very anxious. It could be having to adjust to big events like Christmas or changing schools, facing uncertainty at work, or something simpler like a bus detour that can trigger their anxiety.

Highly focused interests or activities

Many autistic people have intense and highly focused interests, often from a fairly young age. These can change over time or be lifelong. Autistic people can become experts in their special interests and often like to share their knowledge. A typical example is an interest in trains but that is just one of many.

Like all people, autistic people can gain huge amounts of pleasure from pursuing their interests and see them as fundamental to their wellbeing and happiness.  

Being highly focused helps many autistic people do well academically and in the workplace but they can also become so engrossed in particular topics or activities that they neglect other aspects of their lives.  

How common is autism?

Autism is one of the most common childhood onset neurodevelopmental disorders with an estimated prevalence in children of at least 1% (so at least one in 100 children is autistic). There are about 3 to 4 times more boys affected by ASD than girls, although this varies across the spectrum.²

Camouflaging, defined as strategies used to appear less autistic in social interactions, may increase challenges to identify females with autism and contribute to a later diagnosis.³

How is the diagnosis of autism made?

Diagnosing autism can be difficult because there is no medical test, like a blood test, to diagnose the disorder. Doctors look at the child’s developmental history and behaviour to make a diagnosis.⁴

ASD can sometimes be detected at 18 months of age or younger. By age 2, a diagnosis by an experienced professional can be considered reliable. However, many children do not receive a final diagnosis until much older. Some people are not diagnosed until they are adolescents or adults. This delay means that people with ASD might not get the early help they need.⁴

Developmental monitoring is an active, ongoing process of watching a child grow and encouraging conversations between parents and providers about a child’s skills and abilities. Developmental monitoring involves observing how your child grows and whether your child meets the typical developmental milestones, or skills that most children reach by a certain age, in playing, learning, speaking, behaving, and moving.⁴

If you have concerns about the development or behaviour of your child, it is recommended to consult a healthcare professional. If ASD is considered, the healthcare professional may refer your child to a specialist team (the autism team) or to a paediatrician, paediatric neurologist or to a child and adolescent psychiatrist.⁵

The autism team will decide whether to carry out an autism diagnostic assessment and also, if any other assessments are required.

An assessment usually includes:

• reports from all settings (e.g., school, nursery)
• an autism-specific developmental and family history
• observations in more than one setting
• communication, behaviour and mental health assessments
• a physical examination
• tests and assessments for other conditions where appropriate.⁶

The team should explain to you the reason for each test or assessment. You should be given plenty of time to ask questions. Don’t be afraid to ask for explanations or clarification if you need them.¹

At the end of the assessment, you and, if appropriate, your child will be provided with a written report of the autism diagnostic assessment. This should explain the findings of the assessment and the reasons for the conclusions drawn. If there is uncertainty about the diagnosis the autism team may consider keeping your child under review. If your child is given a diagnosis of autism the team will explain how autism is likely to affect your child’s development and function. Specialist interventions may be offered, for example, to support the development of social and communication skills or to help manage behaviour that challenges.²

Remember, early diagnosis ensures that your child and your family have prompt access to support and services in education, health and social care, a route into voluntary organisations and contact with other children and families with similar experiences. All of these can improve the lives of your child and your family.²

What causes autism and can it be treated?

The precise cause of autism is unknown. However, genetic factors play a role making it more likely that the condition is passed on (estimates are between 40-90%). A number of different environmental factors are also thought to play a role in the development of autism.

Factors associated with an increased prevalence of autism include:

• Male sex
• Family history of ASD
• Genetic disorders such as Fragile X
• Chromosomal disorders such as Down’s syndrome
• Environmental factors such as advanced paternal age and very low child-birth weight
• Neurodevelopmental conditions such as learning (intellectual) disability and attention deficit hyperactivity disorder (ADHD)

It is important to note that autism is not caused by emotional deprivation or the way a person has been brought up and there is no link between autism and mumps, measles, and rubella (MMR) vaccine, based on all published research.⁷

More information on risk factors for autism can be found on the Clinical Knowledge Summaries (CKS) website.

Autism cannot be cured, but management tailored to your child can improve their functional abilities to interact with the world around them and to adapt to it. This multidisciplinary and individualised care is a course which evolves with the child, then the teenager and then the adult. As autism persists throughout life so its management must “follow” the patient.

Research suggests that individuals with autism experience some conditions – including underlying medical issues, neurodevelopmental differences, and mental health issues – more frequently than the general population. Diagnosing these conditions can be challenging because many people with autism have difficulty recognising and communicating their symptoms. Common underlying medical conditions include:

• Sleep disorders
• Anxiety
• Depression
• Epilepsy
• Gastrointestinal and immune function disorders
• Metabolic disorders¹³

Seeking help from a healthcare professional for sleep disorders in children with ASD →

Why is a child’s sleep important?

Beginning in infancy, children grow and learn during sleep. Sleep is one of the most important functions of the brain and growth hormone is released during sleep. The first few years of life are marked by significant changes, including critical periods of brain development that are dependent on a child’s experiences of their environment.

These experiences are processed whilst sleeping to make connections in the brain that lead to language acquisition, visual and auditory processing (recognising and interpreting information taken in through the senses of sight and sound), motor development (physical growth, muscle and bone development to facilitate mobility), cognitive (thinking and reasoning) development and emotional regulation. This process is exhausting for the young and requires significant periods of sleep.⁹

Finally, sleep contributes to the performance (physical and intellectual) of all of us, to memory and learning, to the regulation of mood and to alertness.

How much sleep does a child need?

The recommended duration of sleep over 24 hours depends above all on the age of the child. In 2015, the National Sleep Foundation evaluated the optimal sleep durations by age group. These recommendations are summarised in the table below.  

We can see from the table that sleep needs change as children get older. It helps to have an idea of how much sleep your child needs as this will be different depending on their age. However, all children are unique, and some will need more or less sleep than others which is why the recommendations are for sleep ranges.  

Whilst sleep needs change as a child gets older, research shows that a consistent bedtime routine combined with a suitable bedtime environment is helpful in making sure a child gets enough good quality sleep; this applies equally to 2-year-old toddlers and stubborn teenagers.  

National Sleep Foundation Recommended Sleep Duration by Age¹⁰

What is a good night’s sleep?

The duration (length) of sleep, its quality (which influences how a person performs the next day) and its architecture (the basic structure of sleep patterns) vary throughout life, and particularly during the first 5 years. A newborn spends 80% of the day asleep, and pre-schoolers about 50%. Studies have shown the importance of good quality sleep for child growth and development and for family wellbeing.

Here are the main measures of good quality sleep:

• The time taken to fall asleep after lights out (sleep latency) should be less than 30 minutes
• The maximum uninterrupted sleep time (longest time your child stays asleep at night without waking up) should be more than 6 hours
• The total sleep time should be within the recommended range for the child’s age^11,10

If you would like to capture sleep statistics for your child a free to download Sleep Nap Diary App is available to download.

Insomnia and autism: what is the link?

Insomnia in children is defined as repeated difficulty with sleep initiation, duration, consolidation (uninterrupted sleep) or quality that occurs despite age-appropriate time and opportunity for sleep. This makes it more difficult for the child and/or the family to function the next day.¹²

Chronic sleep problems affect anywhere from 50% to 80% of children with autism – and therefore, their parents. Problems include difficulty falling asleep, frequent and prolonged wakenings, shorter consolidated (uninterrupted) sleep, shorter sleep duration or extremely early rising. Sleep issues go hand in hand with daytime behaviours and can affect quality of life for the entire family.

Having both a bedroom environment and daily routines that promote consistent, uninterrupted sleep (often called sleep hygiene) can help, and specialists have created parent-guided programmes to help improve sleep in children with ASD. In some cases, children with significant sleep disturbances may need to be evaluated by a sleep specialist.¹³

Insomnia is one of the most burdensome complaints among parents of children with autism and often the reason they seek help. In a developing child, sleep serves multiple functions, including energy conservation, brain growth, memory consolidation (process of storing recent learned experiences into long-term memory) and cognition (thinking and reasoning).

Given the importance of sleep to daily functioning the consequence of disrupted sleep in individuals with ASD is potentially serious. Recent research has shown that insufficient sleep increases the severity of core ASD symptoms (e.g., repetitive behaviours, social and communication difficulties) as well as other challenging behaviours (e.g., self-injury, tantrums, and aggression).¹⁴

The impact of shorter uninterrupted sleep on autism symptoms has been demonstrated in a recent study which showed that autistic children who slept continuously 60 to 75 minutes less than other autistic children had higher levels of irritability and higher stereotypic behaviours.¹⁵

Another study found that improvement in the duration of the longest uninterrupted sleep episode led to a significant improvement in daytime behavioural problems in autistic children and was also associated with improvement in the quality of life of parents.¹⁶

In general, children with ASD frequently present with:

• Difficulty falling asleep: for example, taking longer than 30 minutes to fall asleep
• Reduced total sleep time: for example, less than 8 hours for a child aged 3 to 5
• Frequent night awakenings of more than an hour which lead to fragmented and therefore less restorative sleep (e.g., less than 6 hours of continuous sleep per night)
• Early awakenings (more than an hour before the desired time to get up)¹¹

What are the causes of insomnia in children with ASD?

There are multiple factors that are thought to contribute to the development of sleep disorders in individuals with autism. A decrease in the secretion of melatonin (a hormone produced by the brain) and a desynchronisation of the internal clock (when the internal clock is no longer in harmony with the environment) in children with ASD are also believed to be partly responsible.²⁴

Find out more about melatonin →

Do sleep disorders worsen autism?

The severity of sleep problems and the severity of autism spectrum disorder may be linked. In autistic individuals sleep disorders will:

• Increase communication disorders and behavioural disorders
• Increase anxiety and mood swings, irritability, motor stereotypies (repetitive behaviours, moves or sounds), aggressive and hostile behaviours
• Reduce the ability to pay attention and understand which may lead to a deterioration in school performance^14,18

In particular, it is the duration of consolidated (continuous) sleep that influences the child’s daytime functioning. In the case of fragmented sleep (less than 6 hours of continuous sleep per night), an increase in behavioural difficulties has been observed in autistic children​​.¹⁵

Additionally, sleep disorders can disrupt family balance by increasing parental stress and decreasing family cohesion.¹⁹

Finally, abnormalities in melatonin production, that are often experienced by children with ASD, could contribute to autistic symptoms in children and adolescents.²⁴

Tips for improving sleep for children with ASD →

Melatonin and sleep

Humans are programmed to be awake during the day and sleep at night. This is made possible by our “internal clock” which regulates our sleep-wake rhythm. This “clock”, which is located in our brain in an area called the suprachiasmatic nucleus (SCN), also controls the secretion of melatonin.

The Endogenous Circadian Clock System

Because melatonin is secreted in response to darkness, certain types of light-emitting devices can suppress its production leading to disrupted sleep.²¹

Natural Secretion Profile of Melatonin

What are the links between reduced melatonin secretion and sleep disorders in children with ASD?

To try to understand the association between melatonin secretion and autism a team of French researchers measured the average levels of melatonin excreted in the urine (melatonin is eliminated from the body in our urine) of 49 children or adolescents with autism and compared them to those of 88 children or adolescents of the same age without autism (the control group). The results showed that 63% of children with ASD had night-time melatonin levels less than half the average levels found in the group without ASD. Lower melatonin production was also linked to the severity of autistic symptoms.²³

Urinary Excretion of Melatonin Metabolite (µg/hour)

Urinary Excretion of Melatonin Metabolite (µg/hour)