What the RAADS-R and CAT-Q measure

Two questionnaires, two different questions

When you book an autism assessment with us, part of the process is a set of standardised questionnaires that we send out and score for you. People often ask what these actually measure, and why a high score on one and a middling score on another can sit side by side without contradiction. This guide explains two of the most useful, the RAADS-R and the CAT-Q, and why the second matters so much for adults who reach midlife without a diagnosis. These are completed as part of the assessment itself, not something to work through beforehand.

Screening is not diagnosis

The first thing to be clear about is that no questionnaire diagnoses autism. These are screening and support tools. They help a clinician decide where to look and what to ask, and they give a structured record of your own experience in your own words. The diagnosis itself rests on a clinical assessment: a detailed developmental history, a review of how traits show up across different settings, collateral information from someone who has known you a long time where that is available, and a judgement made against recognised diagnostic criteria. A score above or below a cut-off never settles the question on its own.

Understanding that distinction takes the pressure off the numbers. A questionnaire that comes back below a threshold does not close the door, and one that comes back high does not open it by itself.

What the RAADS-R measures

The Ritvo Autism Asperger Diagnostic Scale, Revised (RAADS-R) is an 80-item self-report measure designed for use with adults (Ritvo et al., 2011). It asks you to rate a wide range of experiences across four areas: social relatedness, circumscribed interests, sensory and motor features, and language. It also asks you to consider each item both now and in childhood, which helps capture the lifelong pattern that is central to autism rather than a recent change.

The RAADS-R is good at gathering a broad picture of autistic traits across the lifespan. It was designed to assist clinicians in a specialist setting rather than to stand alone, and it performs best in that role. A high total tells us there is a substantial trait load worth exploring carefully. It does not, by itself, confirm anything.

What the CAT-Q measures, and why it matters

The Camouflaging Autistic Traits Questionnaire (CAT-Q) measures something quite different, and for many adults it is the more revealing of the two (Hull et al., 2019). Rather than asking about traits, it asks about the effort you put into hiding them. It has three parts: compensation, meaning the strategies you use to work around social difficulties; masking, meaning actively performing to appear non-autistic; and assimilation, meaning the sense of having to pretend or force yourself through social situations in order to fit in.

This matters because camouflaging is one of the biggest reasons autistic adults are missed for decades. Someone who has spent a lifetime studying how other people behave, rehearsing conversations, copying expressions and suppressing their natural responses can present, in a single appointment, as socially fluent. The traits are still there. What has changed is the amount of effort going into concealing them, and the exhaustion that effort tends to produce.

A high CAT-Q score alongside an apparently smooth social presentation is not a contradiction. It is often the clearest sign that what is visible in the room is a performance refined over many years. This pattern is more common in women, and in anyone who learned early that fitting in felt safer than standing out, which is a large part of why late diagnosis is so common in these groups.

How these fit with the wider picture

Used side by side, the RAADS-R and the CAT-Q answer two different questions. The RAADS-R asks how many autistic traits are present across your life. The CAT-Q asks how hard you have been working to hide them. A person can score modestly on a traits measure precisely because they camouflage so well, and the CAT-Q is what brings that into view.

Alongside these we still use several other instruments where they add something, including the full 50-item Autism Spectrum Quotient (AQ-50), the Empathy Quotient (EQ) and the Reading the Mind in the Eyes Test (RMET). Each has value, and each has real limitations that we keep in mind rather than gloss over. The AQ-50 is a useful measure of self-reported traits, but its results can be pushed up or down by anxiety, low mood or how someone happens to read the questions on the day. The EQ rests on a model of empathy that is increasingly questioned: many autistic people feel other people’s distress intensely while finding it harder to read the social signals, so a low score can mislead as easily as inform. The RMET, which asks you to judge emotions from photographs of eyes, is better understood as a test of emotion recognition than of any deeper social ability, and it carries cultural and linguistic bias built into its design.

There is a broader point behind all of these. Most were built around how autism looks to non-autistic observers, which means they can undervalue the experience of someone whose difficulties are real but do not present in the expected way. This is part of what the research now calls the double empathy problem: understanding runs in both directions, and a mismatch is not simply a deficit on one side.

For that reason no single questionnaire replaces the clinical interview. They inform it, sharpen it, and help make sure nothing is overlooked, but they are read as pieces of evidence to weigh, not verdicts to obey.

What this means if you are considering assessment

If you are still weighing up whether an autism assessment is right for you, the place to start is the AQ-10 on our screening questionnaires page. It is a brief, free self-check you can complete in a couple of minutes, and a score of six or above suggests a formal assessment is worth pursuing. It is worth knowing that the AQ-10 can read low in people who mask well, so if you recognise yourself in descriptions of autism despite a low score, that is still worth taking seriously.

At Caledonian Psychiatry — the first independent medical agency regulated by Healthcare Improvement Scotland — adult autism assessment is carried out remotely across Scotland by Dr David Crocker, an experienced psychiatrist (MRCPsych). The assessment combines these instruments with a full clinical history, and the fee and format are set out in full on our fees page.

References

Hull, L., Mandy, W., Lai, M.-C., et al. (2019) Development and validation of the Camouflaging Autistic Traits Questionnaire (CAT-Q). Journal of Autism and Developmental Disorders.

Ritvo, R.A., Ritvo, E.R., Guthrie, D., et al. (2011) The Ritvo Autism Asperger Diagnostic Scale–Revised (RAADS-R). Journal of Autism and Developmental Disorders.