What makes an adult autism assessment thorough, and do you need cognitive testing?

If you are looking into an adult autism assessment, you may notice that clinics describe very different processes. Some use two or three appointments and others use four or five. Some also include cognitive testing, while others do not. Prices vary too, so it can be hard to know what you are paying for.

This guide uses Australia’s National Guideline for the assessment and diagnosis of autism to explain what a thorough adult assessment includes, whether more sessions means a better assessment, and when cognitive testing is worth adding.

What a thorough adult autism assessment includes

Autism CRC published the National Guideline in 2018 and updated it in 2023. It also describes an assessment in three parts. The guideline’s adult information says the assessment must include all parts, and must always consider every possible explanation for what you are experiencing.

The guideline also says assessments should include in-person contact. Telehealth can be used for some parts, but not for the whole process.

Do more sessions mean a better adult autism assessment?

Not on its own. We could not find any guideline or research that links the number of appointments with a more accurate result. The guideline’s research priorities include reducing the number and length of sessions for people with complex needs, while still covering everything that matters.

The guideline’s adult booklet says that when the findings are not so clear, the assessment may happen over a longer time with more appointments, sometimes with a team. Someone with a long history of anxiety, trauma or ADHD may need more time to tease apart what is going on.

Session counts are also hard to compare. Two 3-hour sessions are more face-to-face time than four 1-hour sessions. A lot of the work happens after you leave, too, in scoring, reviewing records and writing the report. When you compare services, ask about the total hours and what each appointment covers, rather than counting visits.

The building blocks of a thorough assessment

These are the parts the National Guideline और the UK NICE guideline for adults describe. A shorter assessment can still be thorough if it covers them well.

• Your story, now and across your life. A detailed interview about how you think, communicate, relate to others and experience the world.
• Your early development. Autism traits are present from early childhood. NICE suggests involving a family member, partner or other informant, or using documents such as school reports.
• Someone who knows you now. A partner, friend or relative can describe things you may not notice yourself.
• Direct observation. The clinician spends time with you and may use a structured observation tool.
• Standardised tools, used with judgement. The guideline says tools can support the assessment, but should never replace clinical judgement. After all, every tool has some error.
• Other explanations and co-occurring conditions. NICE lists anxiety conditions, including social anxiety and obsessive compulsive disorder, as things to consider. ADHD is also common. A large review found that about 28% of autistic people also have ADHD. The guideline also asks clinicians to consider trauma and refugee experience.
• More than one clinician’s input. When one practitioner leads the assessment, the guideline says at least one other qualified practitioner should have input. Complex presentations may need a team.
• A clear written report and a feedback meeting. The guideline says the report should give a clear outcome, explain the reasoning, and show the evidence for or against each diagnostic criterion. It also says findings should be explained to you before you read the report.

Is cognitive testing necessary?

For many adults, formal cognitive testing is not needed, although your thinking skills are still considered as part of the assessment of functioning. The National Guideline lists cognitive assessment as one option when another condition or a co-occurring condition is possible. Neither the Australian guideline nor the NICE guideline makes formal IQ testing a requirement for every adult.

The clinician does need to consider your general thinking ability and developmental level. The diagnostic criteria ask clinicians to say whether autism comes with or without an intellectual impairment, and to separate autism from intellectual disability. For many adults, school, study and work history give the clinician enough information to do this without formal testing.

When cognitive testing adds value

• You had learning difficulties at school, or a learning disorder or intellectual disability is possible.
• You notice an uneven profile, such as strong reasoning but real trouble with speed, memory or organisation, and you want to understand why.
• There are other concerns about thinking, such as a past brain injury or changes in memory.
• You need detailed evidence of strengths and needs for the NDIS, university or workplace adjustments.
• You want a full picture of how your mind works to plan support, not only a yes or no answer.

Cognitive testing can also be useful when ADHD is part of the question. The Australian ADHD guideline reports a review that found cognitive tests did not make ADHD diagnosis more accurate. Their value is in describing your strengths and challenges, which can shape practical recommendations.

When you may not need it

If your main question is whether you are autistic, your school and work history are clear, and cost is a concern, an assessment without formal cognitive testing may be enough. Cognitive testing adds several hours of testing and scoring, so it adds to the fee. A good service will explain whether they think it would help in your case, and why. Our article do I need a cognitive assessment with my ADHD or autism assessment? goes into this in more detail.

Is there a Medicare rebate for an adult autism assessment?

Medicare has assessment items for complex neurodevelopmental conditions, including autism. The Department of Health says they are for people under 25, and need a referral from a paediatrician or psychiatrist. They allow up to eight allied health assessment services in a lifetime.

For adults aged 25 and over, these items do not apply. As a result, most private adult autism assessments are paid in full by the person. Some private health insurance policies help with psychology costs, so check with your fund. If you have an NDIS plan, ask your plan manager or support coordinator whether an assessment fits your goals.

Questions to ask before you book an adult autism assessment

द National Guideline says services should explain their costs, time requirements, who will be involved and what to expect. These questions can help you compare.

• What does the fee include? Are the report and feedback session included? Are there any extra costs?
• How many hours will I spend with the clinician, and over how many appointments?
• Who will be involved, and what are their qualifications?
• Will you speak with a family member or someone who knew me as a child? What happens if no one is available?
• Which parts happen in person?
• Will you also look at ADHD, anxiety and other possible explanations?
• Do you recommend cognitive testing for me, and why?
• What will the report include, and will you explain the results to me in a meeting?
• How long is the wait, and how long until I receive the report?
• What happens if the result is not autism?
• What support is available afterwards?

Possible outcomes of an adult autism assessment

The guideline notes that it is common for an assessment that considers autism to end without an autism diagnosis. Some people learn that ADHD, anxiety, trauma or a mix of factors explains their experiences better. Either way, a good assessment should describe your strengths and needs and give practical next steps. If you are unsure about the result, the guideline says it is okay to seek a second opinion.

Invictus Health कैसे मदद कर सकता है

Our psychologists and neuropsychologists provide adult autism assessments, and you can self-refer. The assessment starts with a discovery session about your concerns and history. It then moves to the assessment itself, followed by your report and a feedback session to talk it through. Autism assessments are done in person and take about 3 to 4 hours of face-to-face time. Scoring, interpretation and report writing happen afterwards. Assessments are clinically reviewed by Dr Judy Tang OAM, Clinical Neuropsychologist.

An autism assessment is $2,100. With a cognitive assessment it is from $3,300 to $3,600. A combined autism and ADHD assessment is $2,700, or $3,850 with a cognitive assessment. If you are not sure you need a full assessment, a screening is $700. Our ADHD and autism assessments page has the details, and our screening or full assessment guide explains the difference.

If you would like help deciding what to include, book a 15-minute phone call. If cost is a barrier, please talk to us. We have these conversations all the time, and it’s OK to ask.

This article is general information only. Please speak with a qualified health professional about your own situation.