Autism is far more common, and far more varied in how it presents, than many people realise. According to the Australian Bureau of Statistics, there were 290,900 Autistic Australians in 2022, a 41.8 per cent increase from 205,200 in 2018. Prevalence is higher in males than females, at 1.6 per cent compared with 0.7 per cent, though this gap has been narrowing, with the growth rate in identified autism among females considerably higher than among males between 2018 and 2022. This reflects a broader, well recognised issue, autism has historically been underdiagnosed in girls and women, partly because diagnostic tools were developed based on how autism tends to present in boys and men.
This article looks at what autism actually involves, how it can present differently across age and gender, and what a thorough, evidence based assessment process looks like.
What Autism Is, and How It Can Present
Autism is a lifelong neurodevelopmental condition that affects how a person communicates, interacts socially, and experiences the world around them. It is described as a spectrum because it affects each person differently, some Autistic people need significant daily support, while others live largely independently, and presentation can vary considerably by age, gender and individual strengths.
Common areas of difference include social communication and interaction, restricted or repetitive interests and behaviours, and differences in sensory processing, such as being over or under sensitive to sound, light, texture or touch. In children, this might look like delayed or atypical language development, difficulty with back and forth social interaction, intense or narrow interests, or strong reactions to sensory input. In adults, autism can present more subtly, particularly in those who have developed strategies to mask their differences in social settings, which can make presentation harder to recognise and contributes to autism frequently being missed or misdiagnosed as anxiety, depression or another condition earlier in life.
Why so Many Autistic People Are Diagnosed Later, or Missed Altogether
The ABS data highlights a pattern seen consistently in the research, autism prevalence appears to decline sharply with age, not because people grow out of autism, since it is a lifelong condition, but largely because of how identification and diagnosis actually happen. Diagnostic criteria and assessment tools were historically developed based on presentations more common in males, and autistic females are more likely to engage in camouflaging behaviours that imitate socially typical behaviour, which can delay recognition and diagnosis considerably.
This means a meaningful number of autistic children, and particularly autistic girls, are not identified until later childhood, adolescence or even adulthood, sometimes after years of feeling that something is different without having a clear explanation. Late diagnosis is not a failure on the part of the individual or their family. It reflects gaps in how autism has traditionally been assessed, gaps that current diagnostic guidance is specifically working to address.
What a Proper Autism Assessment Involves
Australia has a nationally consistent, evidence based approach to autism diagnosis, set out in the National Guideline for the Assessment and Diagnosis of Autism, developed by Autism CRC and approved by the National Health and Medical Research Council. The Guideline sets out clear recommendations and good practice points for practitioners conducting assessments across childhood, adolescence and adulthood, and specifically addresses the need to consider how autism may present differently across gender, culture and individual background.
A thorough assessment is not based on a single test or checklist. It typically draws on a detailed developmental history, structured observation, standardised assessment tools, and information from multiple sources relevant to the person's life, such as family members, partners, teachers or workplace context where appropriate. For children, this often includes input from parents or carers and, where relevant, educators. For adults being assessed for the first time, the process usually involves a detailed look back at developmental history alongside current presentation, since many adults seeking assessment have spent years developing coping strategies that can mask underlying differences.
The goal of a proper assessment is not simply to arrive at a label. It is to build an accurate, individualised picture of a person's strengths and support needs, which then informs meaningful next steps, whether that is accessing early intervention, education support, workplace adjustments, or simply a clearer understanding of oneself.
Why Timely, Accurate Assessment Matters
An accurate autism assessment can open the door to a wide range of support. The ABS data shows that 84 per cent of Autistic Australians need assistance with at least one daily activity, most commonly cognitive or emotional tasks, communication and self care, yet a substantial proportion report unmet need for further support, with two thirds of those requiring assistance indicating they need more help than they currently receive. Formal diagnosis is often a necessary step to access funded support, including through the NDIS, as well as reasonable adjustments in education and the workplace.
Beyond formal support, many autistic people and families describe diagnosis as providing genuine clarity and relief, a framework for understanding experiences that may have felt confusing or isolating for years, rather than something to be feared. Equally, a thorough assessment process can also identify when presenting difficulties are better explained by something other than autism, which is exactly why a comprehensive, individualised process matters more than a quick checklist approach.
New at CK Health From Mid August
From mid August, CK Health will be launching autism assessment services, expanding the assessment and diagnostic support already offered for concerns including ADHD, intellectual disability and specific learning disorders. This means families and adults in the Newcastle region seeking a thorough, evidence based autism assessment will have access to this service locally, following the structured, whole picture approach outlined in Australia's National Guideline.
Where to From Here
Anyone who suspects they, or their child, may be autistic, whether based on longstanding questions or more recent observations, does not need to have a clear picture of what an assessment involves before reaching out. A proper autism assessment considers the whole person, drawing on developmental history, current presentation and input from those who know the individual best, to build an accurate and genuinely useful picture rather than a quick label.
More detail on Lisa Bailey's approach and areas of interest, along with the new autism assessment service launching in mid August, is available on her Health Hunter profile.
