Early Signs and Symptoms

Signs and Symptoms of Autism Spectrum Disorder

What is Autism?

Autism spectrum disorder (ASD) is a developmental disability , which causes significant social, communication and behavioural challenges. As autism is a spectrum disorder, the combinations of symptoms and challenges and their level of severity varies from person to person.

People with ASD may communicate, interact, behave, and learn in ways that are different from most other people. The learning, thinking, and problem-solving abilities of people with ASD can range from gifted to severely challenged. Some people with ASD need very significant help in their daily lives; others need less.

Autism Diagnosis

Diagnosing ASD can be difficult. There is no specific medical test, like a blood test or a scan, to diagnose disorders like Autism. Doctors look at the child’s behaviour and development to make a diagnosis.

ASD can typically be diagnosed at about 2-3 years of age, when it becomes evident that the child is not meeting its developmental milestones.  However, many children do not receive a final diagnosis until much older. This delay means that children with ASD might not get the early help and interventions that they need, which underpins the importance of early childhood intervention (hyperlink to our EC page) as soon as any developmental delays or challenges are identified and regardless of whether your child has an autism diagnosis or not.

A diagnosis of ASD now includes several conditions that used to be diagnosed separately: autistic disorder, pervasive developmental disorder not otherwise specified (PDD-NOS), and Asperger syndrome. These conditions are now all called autism spectrum disorder.

The diagnosis criteria for autism is specific and set out in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). To meet the criteria for Autism Spectrum Disorder, a person must exhibit the following symptoms to a degree that significantly impairs their daily living:

  • Persistent deficits in communication and social interaction – this includes deficits in social-emotional reciprocity, initiating or responding to social interactions, non-verbal communicative behaviours, difficulties in playing with friends or appropriately adjusting behaviours; and
  • Restricted, repetitive patterns of behaviour, interests or activities – this includes repetitive motor movements or speech, inflexibility, adherence to routines and hypo or hyper reactivity to sensory aspects.

What causes Autism?

Neither the medical nor the scientific community have comprehensively defined all of the causes of ASD. There does seem to be consensus however that there is no “one-factor” responsible for autism. It is thought that there are many causes for multiple types of ASD and many different factors that make a child more likely to have ASD, including some combination of environmental, biologic, and genetic factors.

What are the Early Signs and Symptoms of Autism

People with ASD often have problems with social, emotional, and communication skills these signs of ASD begin during early childhood. Children or adults with ASD might:

  • Not point at objects to show interest (for example, not point at an airplane flying over)
  • Not look at objects when another person points at them
  • Have trouble relating to others or not have an interest in other people at all
  • Avoid eye contact and want to be alone
  • Have trouble understanding other people’s feelings or talking about their own feelings
  • Prefer not to be held or cuddled, or might cuddle only when they want to
  • Appear to be unaware when people talk to them, but respond to other sounds
  • Be very interested in people, but not know how to talk, play, or relate to them
  • Repeat or echo words or phrases said to them, or repeat words or phrases in place of normal language
  • Have trouble expressing their needs using typical words or motions
  • Not play “pretend” games (for example, not pretend to “feed” a doll)
  • Repeat actions over and over again
  • Have trouble adapting when a routine changes
  • Have unusual sensory reactions  – over or under sensitive to sensori stimuli
  • High levels of anxiety
  • Sometimes display aggressive behaviours to avoid stressful situations
  • Lose skills they once had (for example, stop saying words they were using)

ASD occurs in all racial, ethnic and socioeconomic groups. ASD diagnoses are more common in boys than girls, although the gap seems to be reducing. It seems that autism can sometimes get overlooked in girls, particularly girls with normal or high intelligence.

Girls, it is thought, are better at camouflaging their problems, by imitating other people when they’re socialising. Unfortunately, this can be exhausting. Their restricted interests often don’t stand out as unusual too (e.g. celebrities, pop music, fashion, horses, pets, and literature)

Girls with autism may only have one or few close friendships and be intense and possessive about those friendships.

If I think my child might have autism, what should I do?

If you think your child might have ASD or think there could be a problem with the way your child plays, learns, speaks, or acts, contact your child’s GP or other health professional and share your concerns.

If your child has a developmental delay, you may be able to access funding via the NDIS’s Early Childhood Early Intervention (ECEI) approach , even whilst you wait for a diagnosis. You can find more information about accessing funding for early childhood intervention here.

Research shows that early intervention services can greatly improve a child’s developmental pathway. In order to help your child reach their potential, it is very important to get help for developmental delay and ASD as soon as possible. In addition, treatment for particular symptoms, such as speech therapy for language delays, often does not need to wait for a formal ASD diagnosis.

Who can diagnose Autism?

In Australia, an autism diagnosis can be provided by:

  • a paediatrician, psychiatrist or psychologist; or
  • a team of health professionals – a multi-disciplinary approach that will often include a paediatrician, speech pathologist, occupational therapist or other qualified allied health professionals.

A single health professional may be able to diagnose a child with obvious signs of autism. A team approach is necessary for children with less clear symptoms or who have other conditions that make the diagnosis more complicated.

The guideline for diagnosis recommends the following steps:

  1. Assessment of function: assessing thinking and learning, speech and language, daily living skills, friendships and school and identify if they have any developmental delays.
  2. Medical assessment: assessing whether there could be a medical cause for any developmental delays.
  3. Diagnostic assessment: this step is necessary only if doctors can’t find another cause for your child’s behaviour.

The assessment process unfortunately can take a very long time. Many diagnostic health professionals have wait lists of many months and some even up to a year. It can be a stressful time booking that far in advance and then waiting for your child’s autism assessment. The good news is your child doesn’t need a formal autism diagnosis to access support.

The NDIS’s Early Childhood Early Intervention (ECEI) approach is available to all children aged under 7 who have been identified with a developmental delay or disability.

The first step is to meet with an NDIS Early Childhood Partner to discuss your child’s needs. They can give you information about the supports and services available in your local community, provide some short-term early intervention support where appropriate, and request access into the NDIS if this is required.

Alternatively your GP or Health Professional can help accessing NDIS early intervention funding, with more information available here.

Successful early intervention therapies for autism often focus on four primary areas:

Physical Development

This includes Neurodevelopment. Targeting the child’s body and brain, with research showing motor coordination deficits being pervasive across autism diagnoses and being a cardinal feature of ASD [1].

Social Development

The child’s ability to form relationships, communicate, self-regulate and cope with emotions, with research showing children with autism have sensory and motor difficulties that have been found to impact social functioning[2].

Behavioural Development

The child’s behaviour and behaviours are affected by the environment and the child’s physical, social and cognitive development. This is the focus of ABA, as well as other behavioural development therapies.

Cognitive Development

The child’s ability for higher order processing, thinking and learning. This development assists in building a foundation to expand knowledge and improve problem solving by encouraging critical thinking to make decisions.

What is the best method to help a Child with Autism?

It is important to acknowledge that autism remains a highly complex and challenging condition to address, and consequently, there is no one standardised treatment for autism spectrum disorder. That said, the very encouraging news is that there are a range of therapies and modalities that can help many of the challenges associated with autism.

Whilst the research shows that early intervention is more likely to have major positive effects, no matter the age of a person when they are diagnosed, people of all ages and levels of ability can often improve after receiving well-designed interventions.


The most effective therapies and interventions are often different for each person. However, most people with ASD respond best to highly structured and individualised programs. Research shows that early diagnosis and interventions are more likely to have major positive effects on challenges and later skills.

You can read more about Treatment and Services for Autism here.