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Autism spectrum disorder

  • Autism spectrum disorder (ASD) is a developmental disorder most commonly involving problems with communication and social interactions. Children with ASD also often have abnormal behaviours, interests and play.

    ASD is an umbrella term that covers classic autism, Pervasive Developmental Disorder (PDD), Pervasive Developmental Disorder – Not Otherwise Specified (PDDNOS) and Asperger's syndrome. Up until 2013, these conditions were considered separate, but they are now all grouped under the autism spectrum.

    It is important to know that no two children with ASD are exactly the same, although they may have similar problems. ASD can be mild, moderate or severe. The disorder is referred to as a spectrum because there is a wide range of features among people with ASD. Children with mild symptoms are sometimes referred to as 'high functioning'. 

    ASD is a lifelong disorder with no cure. However, early intervention (therapy and support starting at an early age) can be very successful in helping children with ASD reaching their full potential.

    Signs and symptoms

    Children with ASD tend to have difficulties in two main areas:

    • social interaction and communication
    • abnormal behaviours, activities, interests and play.

    Social interaction and communication

    Many children with ASD have poor communication skills, or focus their communication towards objects rather than people. Some children with more severe ASD are not able to speak. 

    There are many children with ASD who have normal language skills, but will still have problems socialising with other people. Their conversations may be one-sided, they may talk excessively, make up new languages (neologism), or repeat certain words and sounds (echolalia).  

    Most children with ASD have difficulties with non-verbal communication, such reading body language and other non-verbal cues (e.g. understanding or expressing emotions through tone of voice and facial expressions). These children also struggle with more complex language, such as sarcasm, and are more likely to take what people say literally. Eye contact is also often difficult for children with ASD.

    A child with ASD may have many unusual ways of socialising. They may only interact with others when they need to, or they might actively talk with others but only about their own special interests.

    Abnormal behaviours, activities, interests and play 

    Children with ASD may display repetitive behaviours, very limited interests or insistence on routine.

    Children with ASD often lack creativity and imaginative play. They may prefer using their senses to explore toys, for example smelling, tasting or staring at the toys rather than playing with them. Some children prefer repetitive or obsessive actions, such as lining toys up in a long line or continuously spinning a car wheel.

    Higher-functioning children with ASD can become intensely interested in one topic, often to the exclusion of other activities or interests.

    Other symptoms

    In addition, children with ASD may be unusually undersensitive or oversensitive to everyday sounds or textures. There are also body movements that are typical of children with ASD, such as repetitive hand flapping and spinning, as well as head-banging and poor coordination. They may also adopt unusual postures or walk on their toes.

    Many children with ASD can also have other difficulties, which include:   

    • restricted eating patterns
    • sleeping problems
    • anxiety
    • behaviour problems
    • emotional difficulties
    • learning difficulties
    • attention difficulties
    • difficulties with planning and organising.

    Intellectual ability

    One of the main factors that affects how a child with ASD behaves and functions is their intellectual ability (i.e. IQ). Children with ASD can range from being severely disabled through to highly intelligent. About one child in four with ASD has an IQ in the normal range or above, but three out of four children with ASD will have some intellectual disability. The child's level of ability is often uneven, with areas of strength and weakness. 

    When to see a doctor

    If you are concerned about aspects of your child's behaviour and development, see your GP and ask for a referral to a specialist pediatrician, speech pathologist or psychologist. Do not try to make a diagnosis yourself.

    Many of the unusual behaviours that occur with ASD are often seen in normal toddlers, which makes the diagnosis quite difficult at times. Many specialists will wait until a child is older than three years of age before assessing for ASD, but you should discuss this with your child's doctor.

    The diagnosis of ASD requires a multi-disciplinary assessment. This means a team – consisting of a pediatrician, psychologist and/or speech pathologist – will assess your child. As features vary so much between children, there is no single or simple test for ASD.  

    Treatment for ASD

    Early intervention is important for helping your child reach their full potential. Your child's treating team or specialist will help to develop an action plan for the family that can include information resources, parent training, strategies for family support, and an action plan for your child.

    Treatment will depend of the needs of each child and the nature of their impairment/s and may include:

    • Speech therapy: most children with ASD have communication difficulties and will benefit from seeing a speech therapist to help them improve their language and social skills in connecting with others through conversation.
    • Medication: may be helpful in some specific situations, especially involving some of the associated problems listed above.
    • Behaviour therapy: a psychologist may help identify triggers for behavioural outbursts and help the family develop ways to avoid and/or manage these issues.
    • Social skills development: an Applied Behaviour Analysis (ABA) therapist works one-on-one with children to help them 'learn how to learn', and to help them develop social and communication skills.
    • Occupational therapy: occupational therapists can help children who are oversensitive to hearing, visual input or touch. They can also help with concentration and focus.
    • Environmental changes: children with ASD prefer a structured and predictable environment and routine. Visual aids such as picture cards (e.g. a picture of a bed that a child can point to) can be very helpful to improve children's understanding and communication and therefore reduce their stress.
    • Special education settings: there are a number of early intervention programs available for children with ASD. If your child attends a regular school, they will be supported by a Student Support Group (or similar arrangement) and a classroom aide. There are also specialist schools that may be more suitable for some children with ASD.

    The needs of your child and family may change over time, and your child's treatment will change to meet these needs.

    What causes ASD? 

    Research suggests that ASD is a genetic condition, but the exact gene thought to cause the disorder has not yet been identified.

    Research continues, with the aim of finding the cause and discovering more treatment options. 

    Autism and vaccinations

    Although the rates of ASD have increased since the 1980s, this is due to increased awareness and changes in the way the disorder is diagnosed, rather than a growing number of people being affected. At the same time, the number of recommended childhood vaccinations has increased, and many parents worry that these two issues are somehow linked.

    A paper was published in 1998 on a potential link between ASD and the measles, mumps, rubella (MMR) vaccine, but this was later proven to be fraudulent and the medical journal retracted the paper. Since then, multiple studies have shown no association between vaccinations and ASD. It is important that you discuss your concerns with your GP or paediatrician, so that you can be fully informed.

    Key points to remember

    • A child with ASD usually has difficulties in two main areas: social interaction and communication; and behaviours, interests and activities/play.
    • If you are concerned about your child, see your GP and ask for a referral to a specialist psychologist or pediatrician. Do not try to make a diagnosis yourself.
    • No two children with ASD show exactly the same signs and symptoms. Because the symptoms can vary so much, there is no single test for ASD.
    • Treatment varies for each child and family and usually changes over time.

    For more information

    Common questions our doctors are asked

    Is there a chance my child may grow out of it?

    People with ASD will not grow out of their condition, but will learn ways to function well in society. Many adults with ASD live very comfortable, successful lives, without others being aware that they have ASD.

    Are interventions expensive?

    The cost of intervention depends on the severity of the ASD as well as the number of consultations needed. The Australian government heavily subsidises early intervention, and also offers support through carer payments/allowances for children with developmental problems. Discuss these financial supports with your doctor.

    When should we start with interventions?

    Interventions can begin as soon as your child is able to interact with health professionals. It may seem like playing games to your child, but they will be learning invaluable life skills, such as socialising and communicating. Children are often diagnosed with ASD after they turn three years old, which is when intervention usually begins.

    Should my child attend a normal school?

    It depends on the severity of the condition. Many children with ASD are encouraged to attend regular schools. Your school can work with you to accommodate any special requirements your child may have in the classroom and in the playground. Your child may be eligible for a teacher's aid, who can provide extra support in the classroom. There are specialist schools available for children severely affected by ASD who need more support that a regular school can provide. 

    Could we have caused ASD during pregnancy or our difficult birth?

    There is absolutely no association between ASD and any birth trauma, medications taken during pregnancy or formula feeding.

    How common is it for children with ASD to have special skills?

    Some people have incredible skills in memory, mathematics, art, music or problem-solving. They are referred to as savants and the condition is very rare (one in a million people). About half of all savants have ASD (autistic savant) and one in 10 children with ASD have some areas of incredible skill, despite their unusual behaviours or difficulties with communication. 

    Developed by The Royal Children's Hospital Strategy and Improvement department, with thanks to our psychologists, paediatricians and General Practitioners for their significant input. We acknowledge the input of RCH consumers and carers.

    Reviewed June 2018.

    Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit


This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.