How long does an adult ADHD or autism assessment take?

The assessment is delivered across three or four appointments over two to four weeks. Total contact time is typically 5 to 7 hours, depending on the pathway (ADHD, autism, or combined AuDHD).

Do I need a GP referral for an adult ADHD or autism assessment?

No. A GP referral is not required to book an assessment with a psychologist. A referral is needed only if you want to claim the Medicare rebate on any therapy that follows the assessment, or if you are accessing NDIS-funded assessment under specific plan conditions.

What is AuDHD and can it be assessed?

AuDHD refers to co-occurring autism and ADHD in the same person. Behavioural Edge Psychology offers a combined assessment pathway that uses both DIVA-5 and MIGDAS-2 with differential interviewing. Combined ADHD and autism is common in adults and a single-condition assessment can miss the second presentation.

Is collateral history from a parent or partner required?

Collateral history is helpful but not always essential. It is standard clinical practice because some core symptoms must be present in childhood for a diagnosis to be made. If a family member or close contact cannot participate, the assessment can still proceed using available records and clinical interview, with the limitations noted in the report.

Is adult neurodivergence assessment available via telehealth?

Yes. Both DIVA-5 and MIGDAS-2 are validated for telehealth delivery. The choice between in-person and telehealth is yours and can vary across appointments within the same assessment.

What does an adult neurodivergence assessment cost in Australia?

Adult neurodivergence assessments are generally self-funded in Australia, as Medicare does not provide a rebate for the assessment itself. NDIS-funded assessment is available in some circumstances for self-managed and plan-managed participants. Detailed fee information is provided at the intake session and on the fees page.

Comprehensive, neurodiversity-affirming diagnostic assessment for adults. Caulfield South and St Kilda, with telehealth available.

The number of adults seeking an ADHD or autism assessment for the first time has risen significantly. For many, the prompt is recognition. Approximately 4.4 percent of Australian adults meet criteria for ADHD (AADPA Guideline, 2022). A child or family member's diagnosis surfaces patterns the adult has lived with their whole life. For others, it is a workplace crisis, a relationship change, or the slow accumulation of social and cognitive exhaustion that finally needs a name. Adult assessment matters because it changes the framework. A clear diagnosis reshapes how a person makes sense of their history, what accommodations they can request at work or in study, and what evidence-based supports are available. At Behavioural Edge Psychology in Caulfield South and St Kilda, adult neurodivergence assessment is delivered with current diagnostic tools, careful clinical interviewing, and a neurodiversity-affirming framework.

What we assess

Behavioural Edge Psychology offers three adult neurodivergence assessment pathways, ADHD-only, autism-only, and combined AuDHD.

ADHD assessment for adults

Comprehensive diagnostic assessment for Attention-Deficit/Hyperactivity Disorder using the DIVA-5 (Diagnostic Interview for ADHD in Adults), structured clinical interview, validated rating scales, and developmental history. The assessment establishes whether the criteria are met under DSM-5-TR, the presentation type (predominantly inattentive, predominantly hyperactive-impulsive, or combined), and the functional impact across life domains.

Autism assessment for adults

Comprehensive diagnostic assessment for autism spectrum condition using the MIGDAS-2 (Monteiro Interview Guidelines for Diagnosing the Autism Spectrum, Second Edition), a neurodiversity-affirming clinical interview that does not rely on observational scoring of social performance. The assessment is supplemented with developmental history, sensory profile, and validated rating scales.

Combined assessment (AuDHD)

For adults where both presentations are part of the picture. The combined assessment uses both DIVA-5 and MIGDAS-2 alongside differential interviewing. Co-occurring ADHD and autism (AuDHD) is estimated in 30 to 80 percent of autistic adults depending on the cohort studied (Hours, Recasens, and Baleyte, 2022), and an assessment that examines only one presentation can miss the other.

All three pathways include the same standard of clinical care. The choice of pathway is made during the pre-assessment intake, based on what you are looking to clarify.

Why a neurodiversity-affirming framework matters

Many adults arrive at assessment with anxiety. Previous experiences with health systems may have been invalidating, especially for adults assessed as children with framings that no longer fit, or adults who have been told they cannot be autistic or ADHD because they have a degree, a job, or a relationship. A neurodiversity-affirming framework starts from a different position.

Autism and ADHD are not disorders to be cured. They are neurological differences with both strengths and significant difficulties. The diagnostic process recognises the cost of masking, the lived experience of sensory sensitivity, the variability of executive function across contexts, and the long-running effort that adults often expend to appear neurotypical. The assessment focuses on the underlying pattern, not on whether a person performs neurotypically in the assessment room.

The assessment process

The assessment runs across multiple appointments to allow for careful clinical work without compressing the diagnostic interview into a single sitting.

Step one, intake session, 60 minutes.

We meet to discuss what you are looking to clarify, your history, and any previous assessments or treatments. This is also where the assessment pathway is confirmed (ADHD, autism, or combined) and any rating scales or developmental history forms are arranged for completion before the next appointment.

Step two, diagnostic interview, two to three hours depending on the pathway.

The structured clinical interview takes place across one extended session or split across two appointments, depending on preference and tolerance. For ADHD, this is the DIVA-5. For autism, this is the MIGDAS-2. For combined assessment, both are used.

Step three, collateral and history.

Where appropriate, and with your consent, collateral history is gathered from a family member, partner, or close contact. This is standard practice for adult neurodivergence assessment because some core symptoms must be present in childhood for a diagnosis to be made. Collateral history is supportive, not determinative.

Step four, feedback and report, 60 minutes.

You receive a feedback session where the findings are discussed in detail, with the diagnostic conclusions, the underlying clinical reasoning, and the practical recommendations. A comprehensive written report follows, suitable for use with GPs, psychiatrists, employers, universities, and the NDIS where eligible.

What you receive

Every assessment includes the following.

A detailed written diagnostic report, including the clinical reasoning, the criteria met or not met, the differential considerations, and the practical recommendations.
A feedback session where the report is discussed in plain language.
A letter for your GP summarising the diagnostic findings and any onward referral needs.
Where relevant, supporting documentation for workplace adjustments, university accommodations, or NDIS access.

The report is written in plain language with the clinical detail in clearly marked sections. It is designed to be a usable document, not a clinical artefact, and clients are welcome to share it with any practitioner or service they choose.

Funding and access

Adult neurodivergence assessments are typically self-funded in Australia. There is no Medicare rebate for the assessment itself, though specific items within the assessment process may attract a partial rebate when delivered alongside a Mental Health Treatment Plan. The practice provides detailed fee information at the intake session and on the fees page.

NDIS-funded assessment is available in some circumstances for plan-managed and self-managed participants where assessment is included in the participant's plan. The practice is NDIS-registered.

Some private health insurance policies include a contribution towards psychological assessment under their Extras cover. Check with your insurer before the assessment.

For adults pursuing assessment to support a workers' compensation or TAC claim, fees can sometimes be billed through those schemes when the assessment is part of accepted treatment. Discuss this at the intake session.

Why Behavioural Edge Psychology

Dr Sarah Fischer is the Principal Psychologist of Behavioural Edge Psychology. She holds a PhD in Psychology and a Master of Psychology (Organisational), and is AHPRA-endorsed in organisational psychology. Her clinical work concentrates on adult presentations, with particular experience in adults presenting after years of high masking and accommodation, including adults in legal, healthcare, and executive roles.

The assessment process is structured to be thorough without being exhausting. The practice's clinical philosophy is empowering and collaborative, which matters in adult assessment because what you take away from the assessment depends in part on whether you feel heard, understood, and accurately described in the report.

Frequently asked questions

How long does the full assessment take?

The assessment is delivered across three or four appointments, depending on your availability and the pathway. Total contact time is typically 5 to 7 hours.

Can I get an ADHD assessment without a referral?

Yes. A GP referral is not required to book an assessment with a psychologist. A referral is needed if you want to claim the Medicare rebate on the intake session or any therapy that follows the assessment.

Will the report support a prescribing doctor?

Yes for ADHD. The diagnostic report is written to the standard required by a prescribing GP or psychiatrist considering stimulant medication, including the clinical reasoning, the differential considerations, and the functional evidence. For autism, no prescribing decision applies, but the report supports onward referrals where relevant.

What if I think I have both ADHD and autism (AuDHD)?

Choose the combined assessment pathway. AuDHD is common in adults and a single-condition assessment can miss the other.

Do I need someone who knew me as a child to participate?

Helpful but not always essential. Collateral history is supportive evidence. If a family member or close contact cannot participate, the assessment can still proceed using available records and the clinical interview, with the limitations noted in the report.

Is the assessment available via telehealth?

Yes. The DIVA-5 and MIGDAS-2 are both validated for telehealth delivery. Some clients prefer in-person, some prefer remote, and the choice is yours.

How soon can I be assessed?

Current waiting time depends on the season and the pathway. Contact the practice for current availability.

Last updated: 12 May 2026

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Adult ADHD and
Autism Assessments

Q: Will the report support a prescribing doctor for ADHD medication?

Yes. The diagnostic report is written to the standard required by a prescribing GP or psychiatrist considering stimulant medication, including clinical reasoning, differential considerations, and functional evidence.

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