What are Autism Spectrum Disorders?

A note on language: Our understanding of autism has grown over the decades, thanks to both an increasing body of research knowledge and the efforts of autistic people and their families to raise awareness. At OTARC, we recognise that there are different opinions about the language used to describe autistic people. Our policy is to confine the use of the term 'Autism Spectrum Disorders' or 'ASD' in clinical and diagnostic contexts - for example, in the titles of research papers, or in communications intended for clinicians.

Everyone with autism is different...

But some of the traits that many autistic people share are:

  • Challenges in communicating and interacting with others
  • Repetitive or 'stereotyped' behaviours, moving their bodies in unusual ways
  • Sensory sensitivities - unconventional or strong reactions to what they see, hear, smell, touch or taste
  • Preference for routines and resistance to change

Key facts

  • Autism can be detected as early as 12 months.
  • Autism is a lifelong condition and there is no known cure.
  • Autism is approximately 3-4 times more common in males than in females.
  • Some autistic adults 'self-identify' - that is, they have not received a formal diagnosis.


As late as the 1990s autism was believed to be a 'rare' condition, affecting about 4 children in every 10,000. The increase to the current prevalence of 1-2% of children is due to the inclusion of AD, AspD and PDD-NOS in the same spectrum of disorders, the way children are diagnosed and a 'real' increase in the number of children affected by the disorder, the cause of which is unknown.

The Australian Bureau of Statistics figures for 2015 show that 164,000 Australians have autism.


The underlying physiological causes of autism are not currently not known. There is however strong evidence for a genetic basis, as autism does run in families. There is a 20% chance of having another child with autism if there is already an autistic child in the family.

Autism is NOT caused by:

  • inadequate parenting,
  • vaccinations or other medical interventions.

Associated Conditions

Some genetic disorders such as Fragile-X Syndrome and Tuberous Sclerosis are more common in those with with autism, as are other conditions such as sleeping problems, ADHD, developmental delay/intellectual disability.


  • ASDs are currently diagnosed according to criteria detailed in the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-5). Subcategories in the previous editions of the DSM (DSM IV-TR) included Autistic Disorder (AD), Asperger's Disorder (AspD) and Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS).
  • ASDs are difficult to diagnose as there are no obvious physical or biological signs and no simple screening tests, such as a blood test. A diagnosis can only be based on the child/person's developmental history and observation of behaviour.
  • Current diagnostic tools allow a trained professional to reliably diagnose ASD as early as 18 months of age. Work is continuing to develop tools for an even earlier diagnosis.

Early intervention for children

OTARC has been researching early identification and diagnosis and has been instrumental in establishing the Government-funded Victorian Autism Specific Early Learning and Care Centre (ASELCC) which provides early intervention services for preschool children with autism and their families.

EIBI seeks to address the child's behavioural, social and communication difficulties with various programs, the most effective of which include some form of Applied Behavioural Analysis (ABA). The Early Start Denver Model one such program, and this is the method of intervention implemented at the Victorian ASELCC.

We recognise that adults with autism may have support needs that may include educational, social communication, speech and language pathology and psychiatric support, or simply societal acceptance.

For more information about autism and resources for individuals and families, visit the websites of: