Understanding assessment

Assessment tools and what to expect

What the questionnaires and observations actually are, what to expect on the day, and why a different set of tools does not mean a worse assessment.

Reviewed by ADHD Scot,

Before we start: what this page is, and isn't

If you have looked into a private ADHD or autism assessment, you have probably seen the tools named (DIVA-5, ADOS-2, QbTest, CAT-Q), and maybe some clips online: a "flying frog" picture book, or being asked to mime brushing your teeth. It is easy to come away worried that unless your assessment used a particular tool, it somehow "didn't count".

This page is here to calm that down. It explains, in plain English, what these tools are, what to expect, and why a good assessment can look quite different from one clinic to the next.

It is general information, not clinical advice, and not a checklist for self-diagnosis or for judging a clinic. We are not telling you which tools are "best", and nothing here should be used to score yourself. If you have questions about your own assessment, the right person to ask is the clinician who carried it out.

On this page

What a thorough assessment actually looks like

Whatever specific tools are used, a credible ADHD or autism assessment in Scotland has the same underlying shape:

  • A detailed clinical interview about your experiences now and growing up, and how they affect your day-to-day life.
  • Developmental and collateral history. Information about your childhood, often from someone who knew you then. Both ADHD and autism have to have been present from early in life, even if nobody noticed at the time.
  • One or more validated tools: the questionnaires and structured observations described below.
  • Consideration of other explanations, such as anxiety or trauma, which can look similar.
  • A written report setting out the reasoning and the outcome.

The tools are one ingredient. The assessment is the whole recipe.

Scotland's approach is deliberately proportionate and neuro-affirming. The National Autism Implementation Team (NAIT), the Scottish Government-funded team that supports neurodevelopmental assessment across Scotland, is clear that there are "many tools and approaches which can be used", and that assessment should be shaped around the individual rather than run to a fixed script. In practice, that means every private provider chooses its own combination of tools, and a good clinician will adapt them to suit the person in front of them. So no two assessments look exactly alike, and that is by design, not a sign that one was less thorough.

NHS and private assessments: how do they differ?

The clinical standard is the same for both. An NHS or a private assessment should meet the standards set out on this page (NAIT's Scottish guidance, SIGN 145 for autism, NICE NG87 for ADHD). What usually differs is how the assessment is organised, not the standard it should reach.

  • NHS assessments in Scotland are carried out by specialist teams. They are free, follow the local neurodevelopmental pathway, and often involve more than one appointment and more than one professional. Waiting times, though, can be very long. (See our NHS pathway and waiting times pages.)
  • Private assessments are paid for and usually much quicker. The model varies more: some private services are full multidisciplinary teams, while others are led by a single consultant psychiatrist or clinical psychologist. A single-clinician assessment is not automatically inferior. What matters is that the assessor is appropriately qualified and registered, and that the assessment has the right shape.

One practical point worth knowing: whether your GP or NHS board will accept a private diagnosis and take over prescribing (shared care) can vary. Our shared care and regulation pages cover this.

Is a multidisciplinary assessment necessary?

This is one of the areas where clinicians genuinely differ, so it is worth understanding rather than worrying about.

  • For autism, SIGN 145 recommends assessment by a multidisciplinary team, and that is the standard NHS model in Scotland. Many clinicians regard a multidisciplinary assessment, one that draws on more than one professional perspective, as the ideal, particularly for complex or uncertain presentations.
  • For ADHD, NICE NG87 recommends that services be organised into multidisciplinary specialist teams, but it also allows the diagnosis itself to be made by a single, appropriately qualified and experienced specialist (such as a consultant psychiatrist or specialist ADHD nurse). So a well-conducted single-clinician ADHD assessment can still be fully in line with the guidance.

In short: a multidisciplinary assessment is widely seen as the gold-standard model, especially for autism and for more complex cases, and it is what the NHS aims to provide. But a diagnosis made by a single, suitably qualified and registered specialist is not automatically less valid, particularly for ADHD. Professional views on this genuinely differ. If it matters to you, it is completely reasonable to ask a provider who will be involved in your assessment, and why. A good clinic will be happy to explain its model.

Children and young people

Assessment also differs by age. For children and young people, the picture leans more heavily on developmental history and on information from the people who know them best (parents, carers and often teachers), and it uses child-focused tools such as the Conners, SNAP-IV, Vanderbilt, SDQ, SCQ or SRS-2 rather than the adult self-report questionnaires. Scotland's children's neurodevelopmental pathway, designed by NAIT, sets out a multidisciplinary, trans-diagnostic approach: looking across autism, ADHD and related differences together, rather than one condition at a time. As with adults, the exact tools vary between services and are adapted to the individual child.

Why no single tool "makes" the diagnosis

This is the most important thing on the page, and it is not our opinion. It is what Scotland's own guidance says.

In its guide for clinicians on using the ADOS-2, NAIT states plainly that the ADOS-2 "is only one tool which can be used… not intended to be used in all assessments or as a stand-alone diagnostic measure", and that it "should not be used as the only evidence that an individual meets diagnostic criteria" (NAIT and the Scottish ADOS Consortium, 2022). The UK-wide guidelines agree:

  • For autism, Scotland's clinical guideline SIGN 145 is explicit that a diagnosis should not be based on any autism-specific instrument alone, but on information from a range of sources together with clinical judgement.
  • For ADHD, NICE guideline NG87 is equally clear: a diagnosis should not be made on the basis of rating-scale or questionnaire scores alone. It rests on a full clinical assessment.

So no questionnaire, computer task or observation "passes" or "fails" you. A skilled clinician weighs everything together. That is exactly why two thorough clinics can reasonably use different toolkits and both be doing a proper job.

Why some tasks look strange, and why that's normal

A lot of the worry online comes from autism assessments, where the ADOS-2 involves activities that feel odd out of context:

  • You might be asked to narrate a wordless picture book (the one people recognise online has frogs floating on lily pads). The clinician is not checking whether you tell the "right" story. They are watching how you use gesture, share attention and put a narrative together.
  • You might be asked to mime an everyday action, such as showing how you brush your teeth. Again, it is nothing to do with the action itself; it is a standard way of observing how you use gesture and demonstrate something without props.

NHS services describe the ADOS this way too. NHS Lothian's own patient information explains it as a standardised, play- and conversation-based observation, not a test you pass or fail. Stripped of that context in a short video, these tasks can look bizarre. In context, they are ordinary, well-established parts of an assessment.

And in Scotland the ADOS is not compulsory. NAIT's guidance for clinicians is explicit that the ADOS-2 "should not be used alone but in combination with broader clinical assessments to determine whether an autism diagnosis is appropriate". So if your assessment did not include the ADOS at all, that can be entirely in keeping with Scottish practice.

Please don't revise for your assessment

It is natural to want to prepare. But when it comes to the tools themselves, our honest advice is: don't over-research them, and don't try to "perform" to them.

Here is why. Reading up on what an assessment "looks for" and then trying to give the "right" answers is, in effect, a form of masking: presenting a polished version of yourself rather than your natural one. And masking is one of the best-documented reasons people get missed, especially women and people diagnosed later in life. If you rehearse, you make it harder, not easier, for the clinician to see the real picture.

The single most useful thing you can do is the opposite of revising: be honest, and be yourself. Describe what daily life is actually like, and what it costs you to keep up, not the version you think you are supposed to give. An accurate account of an ordinary week is worth far more than a rehearsed one.

This is ADHD Scot's guidance, grounded in the research on masking and missed diagnosis and in standard NHS and National Autistic Society advice to bring an honest, everyday account. It is not a direct instruction from any one clinic or guideline.

What is worth doing

Not revising the tools does not mean turning up cold. A few things genuinely help, and none of them involves second-guessing the assessment itself:

  • Jot down real examples beforehand. It is completely normal to freeze when a clinician asks something like "can you give an example of a time you struggle to focus?" Being put on the spot is hard, and ADHD and autism can make it harder still: the memory just goes blank. So before the appointment, note down a handful of concrete, everyday examples of the things you experience: times your attention slips, tasks you avoid or lose track of, moments a social situation felt draining, sensory things that bother you, ways you have learned to cope. This is not the same as rehearsing "the right answers". It is simply jogging your own memory, so an honest picture still comes across even if your mind blanks on the day.
  • Read reviews of the clinician, if you can. To get a general feel for how someone works, it can help to look them up beforehand. Sites like TopDoctors, Doctify, Google reviews or Trustpilot can give a sense of how other people found the experience and the clinician's overall approach. Treat them as a general impression rather than proof of quality: reviews are subjective, can be selective, and are no substitute for the checks that actually matter, such as confirming the clinician is registered with the GMC, NMC or HCPC, which our regulation page walks you through.

And one gentle word of caution on all of this: reviews, comments, and other people's stories online. They are worth a glance, but hold them lightly. Every person presents differently, every clinician assesses a little differently, and how someone personally got on with a clinician is exactly that: personal. Not everyone warms to the person assessing them, and that is completely normal. It does not mean the assessment was wrong, or that your experience will be the same. Try not to place too much weight on any one account: your assessment is your own.

The tools you might see: ADHD

You will not see all of these, and you do not need to. Clinics choose a combination that suits an individual assessment.

  • DIVA-5 (Diagnostic Interview for ADHD in Adults): a structured interview that goes through each ADHD trait with real-life examples, both now and in childhood. One of the most widely used adult tools.
  • CAARS (Conners' Adult ADHD Rating Scales): a questionnaire about ADHD traits, sometimes completed both by you and by someone who knows you well.
  • ASRS (Adult ADHD Self-Report Scale): a short World Health Organization screening questionnaire. A starting point, never a diagnosis on its own.
  • Barkley scales: rate ADHD symptoms and, importantly, how much they actually interfere with everyday life.
  • Wender Utah Rating Scale: asks about childhood, because ADHD must have been present when you were young.
  • QbTest / QbCheck: a short computer task, using a webcam or motion sensor, that measures attention, impulsivity and movement. NICE has reviewed it as a useful aid to assessment, not a standalone test.
  • Brown EF/A Scales: focus on executive function, such as organising, starting tasks, managing time and regulating emotion.
  • Conners (child), SNAP-IV, Vanderbilt, SDQ: questionnaires completed by parents and sometimes teachers when the person being assessed is a child.

The tools you might see: autism

  • ADOS-2 (Autism Diagnostic Observation Schedule, 2nd edition): the structured, play- and conversation-based observation described above. Often called the observational gold standard, but still just one source of information.
  • ADI-R (Autism Diagnostic Interview-Revised): an in-depth interview, usually with a parent or someone who knew you as a child, about your early development.
  • DISCO and 3Di: other detailed developmental interviews covering your history and daily life; the 3Di is often computer-assisted. Any one of these can stand in for the others.
  • RAADS-R (Ritvo Autism Asperger Diagnostic Scale-Revised): a self-report questionnaire about autistic traits across your lifetime.
  • CAT-Q (Camouflaging Autistic Traits Questionnaire): looks at how much you mask or camouflage. Particularly informative for women and late-diagnosed adults, who are more likely to mask.
  • AQ (AQ-10 / AQ-50) (Autism Spectrum Quotient): a short self-report screen, a starting point, not a diagnosis.
  • EQ (Empathy Quotient): a self-report measure of how you relate to other people's emotions.
  • SCQ and SRS-2: questionnaires, often completed by a parent, screening for autistic traits particularly in children.
  • MIGDAS-2: a sensory- and interest-led interview approach that some clinicians use as a more neurodiversity-affirming alternative to observation-heavy tools.
  • Reading the Mind in the Eyes (RMET): a task where you identify emotions from photographs of just the eye region. It gives a sense of emotion recognition and social cognition, and is used as supporting information rather than a diagnostic test in its own right.

You may also come across other supporting measures. None of these, on their own, decides anything.

"My clinic didn't use a particular tool. Was my assessment not thorough?"

Not necessarily, and usually not. Because the guidelines are clear that no single tool decides the outcome, clinics legitimately use different combinations. A psychology-led autism service might rely on the ADI-R or DISCO and a detailed clinical interview rather than the ADOS-2; an ADHD service might use DIVA-5 and choose not to use QbTest. Scotland's NAIT guidance says this directly of even the best-known tool: the ADOS-2 "is not a requirement for a robust diagnosis." Because providers each choose their own tools and adapt them to the individual, the combination will differ from clinic to clinic, and that variation is normal. What matters is the overall shape of the assessment described at the top of this page: a proper interview, developmental and collateral history, at least one validated instrument, consideration of other explanations, and a written report.

If something about your assessment genuinely worries you, for example it was very short, skipped your history entirely, or came with a guaranteed outcome, our regulation page sets out the questions to ask and how to check a clinician's registration. You can also see how listed Scottish providers describe their own approach in our comparison tool.

References

Everything on this page is drawn from published clinical guidance and patient information. The Scotland-specific backbone is the National Autism Implementation Team (NAIT). We also draw on the UK-wide clinical guidelines and on NHS and third-sector patient information.

National Autism Implementation Team (NAIT), Scotland

Clinical guidelines and NHS / third-sector information

See how this site works for our full sourcing standards. We do not use clinic marketing as a source.

This page explains the tools you may come across so you can understand your options and ask good questions. It is general information, not clinical advice, and not a checklist for self-diagnosis or for judging a provider. If you have questions about your own assessment, speak to the clinician who carried it out.

Reviewed by ADHD Scot,