How is autism diagnosed?

By Nikki Campbell

Clinical Lead ASD

Autism Spectrum Disorder (ASD), or autism, is a neurodevelopmental disorder that affects three main areas of an individual’s life: communication, social interaction and repetitive and restricted behaviours.

Around one in every 70 people in Australia (2018) has autism, and it is more common in boys than girls. In 2018 and estimated 353 880 people of the Australian population had a diagnosis of autism. The WA Department of Education has reported that autism accounted for the highest number of children requiring extra support through Schools of Special Education Needs.

Although the cause of autism is unknown, genetic factors have been identified. Siblings have a 35% higher chance of developing symptoms of autism.

Who conducts an autism assessment?

National Guidelines for the assessment of Autism Spectrum Disorder were announced in late 2018 by the Minister of Health. The ‘gold standard’ in terms of diagnosing autism includes a comprehensive assessment by a paediatrician (for children) or psychiatrist (for adults), plus assessments by a psychologist and speech pathologist with specialised training using criteria outlined in the Diagnostic Statistical Manual (DSM-5).

All three professionals must be in agreement with the findings of the assessments before the paediatrician/psychiatrist makes the final diagnosis. This is to ensure that the individual is assessed from different points of view. It also helps prevent misdiagnosis.

child blows bubbles with help of therapist

What does autism assessment involve?

The diagnostic process involves a detailed observation of the individual’s behaviour through a play-based assessment (for children), a language assessment, intellectual assessment, as well as a detailed parent interview.

An individual with autism may also have a language impairment and/or intellectual disability. Severity and support needs are determined by how social communication or repetitive and restrictive behaviours are impacting on the individual’s ability to function at home, school, at work or in the community. 

What are the signs of autism?

Signs of autism can include:

  • Lack of communicative intent (the use of gestures, facial expressions, written or spoken words)
  • Difficulty with the flow of conversation, including reverting conversations back to self-interests, difficulty listening, frequent interruptions or lack of engagement
  • Language difficulties, or difficulty with reasoning and problem solving
  • Speech delays or non-verbal communication
  • Difficulty using and interpreting others’ body language, gestures and facial expressions
  • Problems with play, including difficulties with imaginative and pretend play, as well as engaging in play with peers
  • Difficulty making and maintaining relationships with friends or significant others
  • Difficulty with processing sensory stimuli such as an oversensitivity to noise or adversity to specific textures of food
  • Attention difficulties
  • Behaviours that are repetitive or ritualistic (i.e. having to complete a ritual task before moving onto another task)
  • Obsessive behaviours
  • Anxiety
  • Difficulty with transitions
  • Refusing to go to school or leave the house
  • ‘Black and white’ thinking and inflexibility with rules or routines

If you are concerned that your child may be showing signs of autism, contact your paediatrician. They will make the appropriate referrals based on the findings of their initial assessment.

What happens after an autism diagnosis?

Once a diagnosis is confirmed, an individual with autism is eligible for funding for various services relating to school, therapy and assistance in the community. The level of funding they receive will depend on the individual’s support needs at any given time. Severity ratings are not meant to inform funding. Instead, they are a snapshot of the needs of the person diagnosed with autism at the time of diagnosis. Severity ratings may fluctuate over the lifespan of the individual.

There is a significant body of evidence that suggests that early intervention is the best solution and leads to the best outcomes in terms of therapy. 

girl writes in a book with pink pen

At Therapy Focus, we offer autism assessment services through our trained and highly experienced psychologists and speech pathologists. A referral for an assessment from a paediatrician or psychiatrist is required. For more information, or to book an assessment, simply contact us

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