Diving into Diagnosis: How to get an Autism or Intellectual Disability Diagnosis for Your Child in Australia (and What It Means for NDIS)
Navigating the path to diagnosis for Autism Spectrum Disorder (ASD) or Intellectual Disability (ID) is daunting for parents and carers. With so many different terms, professionals, and processes involved, it’s no wonder families often feel overwhelmed.
One of our missions at RippleAbility is to demystify the processes, labels, and professionals involved for any healthcare process.
Whether you’re just starting to explore a diagnosis or are preparing to apply for NDIS funding, this article outlines the main pathways to ASD or ID diagnosis, what to expect, and where to go for support. As always, if any of this is unclear, please drop us a call or email and we’re happy to answer your questions.
What is Autism Spectrum Disorder (ASD)
Autistics are born with and demonstrate differences in brain style to children who develop “typically”.
Autism is considered a neurodivergence and it is part of a spectrum of ways that human brains can develop. Under the neurodivergence umbrella are other differences in development, including attention deficit hyperactivity disorder (ADHD), dyslexia, obsessive compulsive disorder, down syndrome, and epilepsy (and many more).
In autism, these differences in brain style are put into three areas: language and communication, sensory use and interests, and social relationships and emotional responses.
In language and communication, autistics tend to miss sarcasm, communicate in an overly honest and blunt manner, find non-verbal gestures like eye contact and tone of voice difficult to read in others and use themselves, and have little interest in social chit-chat.
Many autistic people have heightened sensory awareness or they use sensory stimulation to re-regulate. This can mean that they can be distressed by loud noises or bright lights, or they may seek out and repeat certain sounds or physical movements (“stimming”).
Autistic people prefer routine and schedules, and they often feel uncomfortable in busy social environments. This doesn’t mean they don’t want to socialise, just that they may have strong social preferences, such as one-on-one settings or socialising over an activity such as a boardgame or talking about a special interest topic.
These differences can be demonstrated differently in boys and girls.
Diagnosing Autism Spectrum Disorder (ASD)
There are two main pathways for an ASD diagnosis in Australia, and which one is right for your child may depend on your child’s other conditions, your family’s goals (such as access to the NDIS), and availability of professionals.
1. ASD Diagnosis by a Single Clinician
A clinical psychologist, paediatrician, child psychiatrist (or neurologist, though infrequently) can provide a standalone diagnosis of ASD. This is often appropriate for families who want a thorough psychological assessment or do not yet have access to a paediatrician.
This pathway requires an appropriate referral from a GP.
The clinician will complete a comprehensive diagnostic assessment and report based on gold-standard tools and criteria (typically from the DSM-5).
Minimally, this will involve a parent interview, school observation, questionnaires, child assessment, assessment of adaptive behaviour, and a report.
This diagnosis is sufficient for services, including the NDIS and must be categorised as level 1, 2, or, 3, depending on how severely the autism behaviours interfere with the person’s everyday functioning.
Medicare does not provide any rebates for assessment.
You should expect your clinician to inform you of the process, costs, and timeline of this assessment process early in the discussion. Specialist clinicians in Australia may have received additional training following the Autism CRC best practice guidelines. While not needed for the diagnosis, this may be an additional assurance of their clinical ability.
Frequently, a paediatrician or child psychiatrist may conduct the parent interview, and then refer to a clinical psychologist or occupational therapist for “suspected neurodivergence”. One or more of these allied health professionals will then conduct the school observation and child assessment.
2. ASD Diagnosis via Medical and Allied Health Team
If your child’s condition is medically or intellectually complex or the presentation of ASD is nuanced, the clinician will recommend involvement of other professionals to perform a consensus diagnosis.
Often the process is as follows:
A paediatrician or child psychiatrist initiates the process and may refer to a clinical psychologist or occupational therapist for additional diagnostic evidence.
The paediatrician may initially diagnose “neurodivergence,” followed by allied health assessments to confirm ASD.
This collaborative approach is often taken when your child is medically or intellectually complex.
What is Intellectual Disability (ID)
A child with intellectual disability will demonstrate limitations on their thinking abilities, learning capacity, and everyday activities needed to live independently.
This can mean that the person has differences in the way that they approach problem solving, socialising, or making judgements of a situation. In everyday life this may look like difficulties with reading, math, and memory, amongst other cognitive difficulties.
Socially, people with intellectual delay may have difficulty with empathy, making and keeping friendships, or follow rules.
Frequently, these differences can lead to difficulties in independence in areas of personal care, maintaining a job, managing money, and organising themselves at school and work.
Diagnosing Intellectual Disability (ID)
A diagnosis of intellectual disability requires more than just concerns about learning or development—it involves formal testing and must meet specific criteria.
Key Points:
Only a psychiatrist, clinical psychologist, or neuropsychologist trained in intellectual assessments can formally diagnose ID.
The assessment includes:
A standardised IQ test
Evaluation of adaptive functioning, often using tools like the Vineland Adaptive Behaviour Scales (Vineland-II) or WHODAS 2.0 (for those over 17).
A GP referral is typically needed.
The diagnosis must align with DSM-5 criteria.
For NDIS access, the ID must be classified as moderate, severe, or profound.
Why does diagnosis matter
Diagnosis is one of the ways our healthcare system understands who needs supports and what level of support they may need.
This may seem painful or difficult, and at RippleAbility, we often complain about the difficulty families have accessing support when they are so clearly in need. However, this system is important as different people have the skills to assess what is happening psychologically or medically (e.g., psychiatrists or psychologists) to those who process the support systems (e.g., NDIS).
In order to understand who needs support and how much support, the label is an effective way to communicate a formal agreement of difficulty.
Hang in there!
Funding for Diagnostic Assessments
One of the most common questions we hear is: Can I get funding for these assessments?
Unfortunately, NDIS does not fund diagnostic assessments.
However, Medicare may provide up to $400 towards the cost if a paediatrician refers your child specifically for assessment to an allied health professional.
NDIS Eligibility: Age Matters
Understanding the age-related system transitions can make a big difference in planning your child’s supports:
Birth to 9 years: Support and early intervention are typically handled by an early childhood approach partner; these are different in every state and territory. Here in WA, WANSLEA is the National Disability Insurance Agency (NDIA) partner however, this can be different in other states and territories.
9 years and over: The case transitions to NDIS, but only if the child has a NDIS-recognised diagnosis (e.g., ASD or ID).
A diagnosis of Global Developmental Delay (GDD) is not sufficient for NDIS access after age 9.
If your child is under WANSLEA (or another ECA Partner) with GDD, they will need a formal ASD, ID, or other appropriate diagnosis to transition to NDIS at age 9.
You can find out more about early childhood approach partners here.
In Summary
Every child is different, and every family’s journey is unique. There’s no perfect roadmap—but understanding the key players and processes can help you make informed decisions. If you’re unsure where to start:
Talk to your GP or paediatrician about your concerns.
Seek out a clinical psychologist trained in developmental assessments.
Keep in mind the tools and reports most recognised by the NDIS: DSM-5 criteria and Vineland-II.
If things still feel unclear, we’re happy to chat to you. Our navigators don’t need a diagnostic label to be able to help you figure out the best path for your child.
If you need support or a referral, RippleAbility is here to guide you every step of the way.
