How long does an adult autism assessment take?

The process typically involves several hours of clinical interviews and testing. At Behavioural Edge, this includes a developmental history interview, a diagnostic observation using tools like the MIGDAS-2 or ADOS-2, and time for the clinician to review previous reports and score standardized questionnaires.

Can I use NDIS funding for an autism assessment?

If you are already a participant of the NDIS and have funding under 'Capacity Building,' you may be able to use your plan for an assessment. However, the NDIS does not typically fund the initial diagnostic assessment required to gain entry to the scheme.

Is it possible to be diagnosed with autism later in life?

Yes, many adults, particularly women and those who 'camouflage' or mask their traits, are not diagnosed until adulthood. A late diagnosis can provide significant clarity, self-understanding, and access to appropriate supports and workplace adjustments.

What is the difference between MIGDAS-2 and ADOS-2?

The ADOS-2 is a semi-structured, standardized assessment often considered the 'gold standard.' The MIGDAS-2 is a more sensory-based, conversational interview technique that is often preferred by neuroaffirming clinicians for its ability to capture the internal experience of autistic adults.

Do I need a referral from a GP for an autism assessment?

You do not strictly need a GP referral to undergo a private psychological assessment. However, seeing a GP or psychiatrist first may allow you to access Medicare rebates (such as through a Mental Health Care Plan or Complex Neurodevelopmental Disorder items) to help offset the cost.

How Is Autism Assessed and Diagnosed in Adults and Why Do Hormones Change Everything?

Sarah Fischer
Apr 3
10 min read

If you are someone who has started to wonder whether you might be autistic, you are far from alone. Increasing numbers of adults are being assessed for autism across all age groups and genders. For some, the prompt is a child or family member's diagnosis that sparks recognition of similar patterns in themselves. For others, it is a life transition, a workplace crisis, the end of a relationship, or the accumulation of decades of social exhaustion and burnout that brings them to the point of seeking answers. For women in their 40s and 50s, the hormonal changes of perimenopause are an increasingly recognised trigger, as strategies that sustained decades of work, relationships, and parenting can stop working when the neurobiological landscape shifts.

Adult autism assessment session at Behavioural Edge Psychology, Melbourne — Image by Holiak on Freepik

This post explains how autism is assessed and diagnosed in adults, what role cognitive testing plays in that process, and why the perimenopausal and menopausal transition is an important consideration for women seeking assessment in midlife.

How Is Autism Diagnosed in Adults?

There is no single test that diagnoses autism. The process is a clinical formulation, which means an experienced psychologist draws together evidence from multiple sources to determine whether the pattern of an individual’s development, experiences, and current functioning meets the diagnostic criteria set out in the DSM-5-TR (American Psychiatric Association, 2022).

Best practice assessment uses multiple methods and multiple informants. Clinical guidelines from the UK’s National Institute for Health and Care Excellence (NICE CG142, 2012/2021) and the Scottish Intercollegiate Guidelines Network (SIGN 145, 2016) recommend a comprehensive approach that includes a detailed developmental history, structured or semi-structured clinical interviews, behavioural observation, self-report and informant questionnaires, and consideration of differential and co-occurring conditions.

The Diagnostic Interview

The core of an adult autism assessment is the diagnostic interview. Two widely used tools are the ADOS-2 (Autism Diagnostic Observation Schedule, Second Edition; Lord et al., 2012) and the MIGDAS-2 (Monteiro Interview Guidelines for Diagnosing the Autism Spectrum, Second Edition; Monteiro & Stegall, 2018).

ADOS-2

The ADOS-2 Module 4 has long been described as a gold standard observational tool for verbally fluent adults (Maddox et al., 2017; Caton et al., 2023). It uses structured activities to observe social communication in a standardised way. It is a valuable source of data, but it has limitations for women. Research has found that autistic females score lower on many ADOS-2 items than autistic males (Rea et al., 2023), and that the tool’s sensitivity is reduced for females (Kamp-Becker et al., 2018). For women who have spent decades learning to perform socially, the ADOS-2 carries a real risk of false negatives when used as the primary decision-making tool.

MIGDAS-2

The MIGDAS-2 takes a different approach. It uses a qualitative, sensory-based, narrative interview format that generates a comprehensive behavioural profile across social communication, sensory processing, and restricted interests (Howe & O’Rourke, 2024). Its conversational style can surface patterns that structured observation tasks do not elicit, particularly in people with internalised or high-masking presentations.

Screening and Self-Report Measures

Screening questionnaires are used to help determine whether a comprehensive assessment is warranted and to contribute data to the overall picture. For women, the GQ-ASC (Girls Questionnaire for Autism Spectrum Condition, modified for adult women; Brown et al., 2020) has shown good discriminative validity, correctly identifying 80% of autistic women at a cutoff score of 57. The CAT-Q (Camouflaging Autistic Traits Questionnaire; Hull et al., 2019) measures the extent and nature of social masking, compensation, and assimilation. For women in midlife who present as socially capable while expending significant cognitive effort to do so, the CAT-Q captures what observation tools can miss.

Adaptive Functioning

One of the most consistent findings in the autism research literature is that autistic adults without intellectual disability show a pronounced gap between their cognitive ability and their real-world adaptive functioning (Tillmann et al., 2019; McQuaid et al., 2021). This gap tends to widen with age and is more pronounced in those with higher IQ. For women who have achieved professionally and appear to be managing well, an adaptive functioning assessment using tools such as the ABAS-3 (Adaptive Behavior Assessment System, Third Edition; Harrison & Oakland, 2015) can reveal the hidden functional cost of their autism in ways that cognitive testing alone cannot. The ABAS-3 uses a rating scale format completed by the individual and an informant, covering communication, social participation, daily living, and self-management across home, community, and work settings.

What Role Does Cognitive Testing Play?

Cognitive assessments do not diagnose autism. No cognitive test can confirm or exclude a diagnosis. Their role within an autism evaluation is to characterise an individual’s cognitive profile, support differential diagnosis, and inform accommodations and support recommendations.

A meta-analysis by Velikonja, Fett and Velthorst (2019) aggregated data from over 1,800 neurodivergent individuals and found a consistent pattern on the Wechsler intelligence tests. Autistic children and adults showed typical-range performance in verbal and nonverbal reasoning, with a significant weakness in processing speed (approximately one standard deviation below the mean) and slightly reduced working memory. The researchers were explicit that this pattern is not sufficiently sensitive or specific to be used for diagnostic purposes. Its value lies in identifying strengths that can be supported and difficulties that may benefit from workplace or educational accommodations, such as additional time for tasks.

Executive function testing can also be informative. A meta-analysis by Landry and Al-Taie (2024) found that autistic individuals show consistent difficulties with cognitive flexibility across the lifespan. The D-KEFS (Delis-Kaplan Executive Function System; Delis, Kaplan & Kramer, 2001) provides standardised assessment of multiple executive function components, including cognitive flexibility, inhibition, verbal fluency, and planning. Autistic adults commonly show relative difficulty on D-KEFS tasks that require set-shifting and switching, while performing comparably to controls on more structured conditions within the same tests. This within-test variability can be clinically informative, particularly for women whose high verbal ability may mask underlying executive function difficulties in everyday settings.

In the Australian context, cognitive assessment data is relevant for NDIS applications and workplace accommodation reports, where quantified evidence of functional impact is required.

Why Perimenopause and Menopause Changes Everything

If you are reading this as a woman in your 40s or 50s, the timing of your growing awareness may be connected to something beyond just increased public knowledge about autism in women. The hormonal shifts of perimenopause and menopause interact with autistic neurology in ways that can amplify existing difficulties, unmask previously compensated traits, and bring a person to a point of crisis that prompts them to seek assessment for the first time.

The Research

Moseley, Druce and Turner-Cobb (2020) conducted the first study on autism and menopause. In a focus group with seven autistic women aged 49 to 63, participants described autism-related difficulties, including sensory sensitivity, emotion regulation, and social communication, worsening during the menopausal transition. For some, previously effective masking strategies became completely unsustainable. Two participants who were undiagnosed at the time explicitly linked their discovery of their autism to the difficulty of this period.

Brady et al. (2024) expanded these findings, describing the autistic experience of menopause as “a perfect storm.” Participants reported that late discovery of autism often followed a lifetime of struggle, with identification triggered only by reaching a breaking point during perimenopause. Some reported that their perimenopausal symptoms began as early as age 38, and several described clinicians who had not recognised their symptoms, perceiving them to be too young for perimenopause.

Groenman et al. (2022) provided the first quantitative evidence that autistic women experience increased menopausal symptoms compared to non-autistic women, with higher psychological and physical symptom scores. They also found that greater menopausal symptom severity was associated with higher autistic trait severity, suggesting a bidirectional relationship between hormonal change and autistic presentation.

A 2025 systematic review by Grant et al. examined all available research and grey literature on autism and menopause. The review found consistent evidence of increased symptom severity, impacts on work and relationships, and an interrelationship between menopausal symptoms and autistic identity. It also found that no studies had yet evaluated interventions designed specifically for autistic people going through menopause.

What This Means for Adult Autism Assessment

For clinicians, these findings have practical implications. A woman presenting in her 40s or 50s with worsening anxiety, cognitive difficulties, sensory overload, social withdrawal, and burnout may be experiencing perimenopausal symptom exacerbation of lifelong, previously compensated autism. The risk of diagnostic overshadowing is significant. Her symptoms may be attributed to perimenopausal mood disorder, generalised anxiety, or depression without the underlying developmental pattern being identified.

The key question in assessment is whether the presenting difficulties have a lifelong developmental trajectory that predates the menopausal transition. Gathering menstrual and hormonal history alongside the developmental history interview can help clarify whether the current presentation reflects a longstanding pattern amplified by hormonal change, or a genuinely new onset.

Jenkins et al. (2024) found that autistic people who entered menopause unaware of their autism reported greater difficulty overall. This suggests that earlier identification, before the menopausal transition, may improve outcomes and coping. For women who are being assessed now, understanding this interaction between hormones and autistic neurology is part of making sense of their experience.

What to Expect from an Assessment

A comprehensive adult autism assessment at Behavioural Edge Psychology typically includes a detailed developmental and life history interview, a structured diagnostic interview (such as the MIGDAS-2), self-report and informant-report questionnaires (including autism-specific screening tools and measures of camouflaging and sensory processing), adaptive functioning assessment using the ABAS-3, and cognitive assessment using the WAIS-IV/V and D-KEFS where this is indicated by the referral question or will support NDIS, workplace, or medicolegal applications. The process is collaborative, trauma-informed, and neurodiversity-affirming. We are particularly experienced in assessing adults whose autism has been missed or misdiagnosed.

If you are wondering whether what you have been experiencing might be autism, you do not need to have all the answers before seeking an assessment. The purpose of the assessment is to help you understand your pattern, not to prove that you are “autistic enough.”

FAQs

Q: How is autism diagnosed in adults?

A: Autism is diagnosed through a clinical formulation that draws together evidence from multiple sources, including structured diagnostic interviews, self-report questionnaires, developmental history, and behavioural observation. No single test diagnoses autism. Best practice guidelines recommend a multi-method, multi-informant approach.

Q: Can a cognitive test diagnose autism?

A: No. Cognitive assessments such as the WAIS-IV/V and D-KEFS do not diagnose autism. They characterise an individual’s cognitive profile, including intellectual functioning and executive function, to support differential diagnosis and provide evidence for accommodations and NDIS applications. Autistic adults often show a pattern of strong reasoning with reduced processing speed and difficulties with cognitive flexibility, but these patterns alone are not diagnostic.

Q: Why are so many women being diagnosed with autism in their 40s and 50s?

A: Many women were missed in childhood because diagnostic tools and criteria were developed primarily from male presentations. The hormonal changes of perimenopause can amplify autistic traits and erode previously effective masking strategies, bringing women to a point of crisis that prompts assessment for the first time.

Q: What is the connection between menopause and autism?

A: Research shows that the hormonal shifts of perimenopause and menopause can worsen sensory sensitivity, emotion regulation, executive functioning, and social communication in autistic women. Some women only discover they are autistic during this transition, when their compensatory strategies become unsustainable.

Q: What tools are used to assess autism in adult women?

A: Commonly used tools include the ADOS-2 (observational assessment), the MIGDAS-2 (qualitative narrative interview), the GQ-ASC (screening tool validated specifically for adult women), and the CAT-Q (camouflaging questionnaire). Cognitive testing with the WAIS-IV or WAIS-V characterises the cognitive profile, the D-KEFS assesses executive function, and the ABAS-3 measures adaptive functioning. Together these provide a comprehensive picture for diagnosis, NDIS applications, and accommodation recommendations.

Q: What is the MIGDAS-2 and why is it used for women?

A: The MIGDAS-2 is a sensory-based, qualitative diagnostic interview that generates a behavioural profile through conversation rather than structured tasks. Its narrative format can surface patterns that observation-based tools may miss, particularly in adults with internalised or high-masking presentations.

Q: Can you get an autism assessment in Melbourne?

A: Yes. Behavioural Edge Psychology in Caulfield South and St Kilda offers comprehensive adult autism assessments with particular expertise in assessing women in midlife. The assessment process is collaborative, trauma-informed, and neurodiversity-affirming.

Q: Is adaptive functioning assessment required for NDIS access with autism?

A: For Level 1 autism diagnoses, the NDIS requires evidence of reduced functional capacity. Tools such as the ABAS-3 (Adaptive Behavior Assessment System) are used to demonstrate functional impact across communication, social participation, daily living, and self-management domains. Level 2 and Level 3 diagnoses receive automatic access without additional functional evidence.

About the author

Dr Sarah Fischer is the Principal Psychologist of Behavioural Edge Psychology, with locations in Caulfield South and St Kilda, Victoria. She holds a PhD and Master of Psychology (Organisational) and is endorsed by AHPRA in organisational psychology. Her clinical work spans therapy for trauma, workplace psychological injury, and neurodivergent assessment, alongside organisational consulting and medicolegal practice.

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