Frequently asked questions

Below are answers to the most common questions about our autism assessments, including the process, costs, and what to expect. If you don’t see your question here, please contact us, and we’ll be happy to help.

About autism

What are the causes of autism?

The causes of autism are not known, but it is recognised as a ‘neurodevelopmental’ condition. That is, it has to do with how the brain develops. Genetic factors play a part in many cases. For that reason it is important for us to gather details of family history of autism or certain other conditions.

How many people have autism?

While estimates vary widely, a figure recognised widely is just over 1% of the population. This figure was published in research carried out by the Clinical Director of the NDAS team on behalf of the Government.

Are there different levels of autism?

Yes. While everyone diagnosed with autism has an official classification of ‘Autism Spectrum Disorder’, this is further divided depending on whether there is also intellectual disability or impairment of language. Most people on the autism spectrum do not have these additional impairments, but when you receive a diagnosis it will state the overall diagnosis and the level.

Is there still a diagnosis of Asperger’s Syndrome?

From January 2022 the World Health Organisation no longer divided autism into different conditions (Childhood Autism, Asperger’s Syndrome, etc.). The same step was taken with the American international classification in 2013. However, a person keeps their original diagnosis (unless they for any reason have a diagnostic review). There will therefore be very many people with Asperger’s Syndrome for a long time to come. Asperger’s Syndrome was marked by normal intelligence and language function. Now these individuals would just get a diagnosis of Autism Spectrum Disorder.

Is there a diagnosis of PDA (Pathological Demand Avoidance Syndrome)?

No. This was put forward for consideration as a diagnosis but it did not reach the standards needed to be recognised as a separate condition. However, we do recognise that there are people who show the features described as ‘pathological demand avoidance’ and at times we may refer to these features in describing an individual’s behaviour.

Can autism be helped by medication?

There are no medications for autism. However, autistic people often have additional difficulties for which medication may be required. These conditions include anxiety, depression and ADHD.

Is autism lifelong?

Yes. Autism is regarded as a lifelong neurodevelopmental condition. However, the way it affects people can change over the course of time. Research has shown that in a small number of cases (just under 10%), the features of autism change to the point where they are no longer considered as impairments and would no longer meet diagnostic thresholds on reassessment.

Can I self-diagnose?

No. While many individuals come to us after self-identifying as autistic, it’s important to understand that autism is a complex condition, and only a formal assessment by trained professionals can confirm the diagnosis. These professionals are able to assess the full range of criteria, including behaviours and traits that overlap with ADHD, anxiety, OCD, and other conditions which can share similar characteristics.

About our assessments

Do I need a referral from a GP?

If you’re a private patient, no referral is required – you can self-refer. However, if you're being referred by the NHS or another health organisation, we will need a referral from a GP, psychiatrist, or other healthcare professional. We will request this directly from them as part of our standard process.

Can I request an assessment through the NHS?

While many of our patients are referred to us by the NHS, Right to Choose (RTC) is not available in Scotland. This means the NHS will select a provider for your assessment, and you won’t be able to request NDAS specifically. However, if the NHS refers you to us, we will be happy to proceed with your assessment.

What is an informant, and why do I need one?

An informant is someone who has known you since childhood – usually a parent or grandparent. They provide crucial insights into your early development and current behaviours.

The informant’s role involves: 
- Completing our Early Development Questionnaire.
- Participating in an interview as part of the assessment process to provide additional context on your history and present behaviours.

I don’t have a suitable informant. Can I still get an assessment?

Since autism begins in childhood, involving someone who knew you as a child generally leads to the most accurate diagnosis. However, if you don’t have a parent, grandparent, or guardian available, we will ask you to involve someone who knows you well now – ideally a sibling, partner, or close friend.

If you have no informant at all, we can still conduct your assessment. However, in these cases, we may request additional information, such as school reports or health records, to ensure we gather a complete picture.

How long is your waiting list?

At NDAS, we keep our waiting times low. Appointments are often available within two weeks, and typically no longer than a month.

Do you offer online video assessments?

All our assessments are conducted in person at our diagnostic centre in Glasgow. In exceptional circumstances, we can offer online assessments for individuals who are unable to travel. However, if we have any concerns about the accuracy of an online assessment we will arrange a follow-up assessment (at no extra cost) to ensure a reliable outcome.

Autism is a complex condition, and in-person behavioural observation is the best way ensure an accurate result. Our clinicians assess non-verbal communication, eye contact, and other subtle behaviours that are best observed face-to-face.

How long does the assessment take?

The in-person assessment typically lasts around two hours, but the exact duration depends on when our team has gathered enough information to reach an accurate conclusion.

Will I receive my diagnosis on the same day as my assessment?

Yes, in most cases, adults and children receive their diagnosis at the conclusion of their assessment, following a multidisciplinary team meeting. In rare cases where additional review is needed – particularly for children – we may arrange a follow-up assessment at no extra cost.

How much does an assessment cost?

An assessment costs £2186 for both adults and children.

How can I pay?

Payment is requested in advance of your assessment. Once your appointment is confirmed, an administrator will email you with the date, time, and payment instructions.

My child is younger than six. Can they still be assessed?

Yes, we can assess children of any age. However, for very young children, we may first gather information from you to determine whether an immediate assessment is appropriate. In some cases, other local services – such as schools and healthcare providers – may need to collaborate over time to develop a clearer picture before an autism assessment is sought.

What is a diagnostic report, and when will I receive it?

A diagnostic report is a detailed document outlining your entire case, including early developmental history, the informant and clinical interviews, and any other information gathered by our clinicians during the assessment process. It will state whether you meet the diagnostic criteria for autism according to the World Health Organisation’s ICD-11 classification. You will receive your report within a month of your assessment.

If you were referred by the NHS or another organisation, your GP or healthcare professional will also receive a copy. Otherwise, your report is not shared with any third party, including your informant. If you are diagnosed with autism, you will also receive a one-page Diagnostic Statement to help you access support in education or the workplace.

Do you offer ongoing support after my assessment?

No, NDAS is a diagnostic service only. However, if you receive a diagnosis of autism, we will guide you towards appropriate post-diagnostic support services. The formal support available to you will depend on your individual needs, and may include assistance in education, employment, social care, or access to benefits. Regardless of your diagnosis, we will provide tailored recommendations to help you take your next steps with confidence.

Will my diagnosis be accepted by my school, employer, or other organisations?

Yes. A diagnosis from NDAS is recognised and accepted everywhere, including health organisations, schools, insurers, and courts, both in the UK and internationally.

Can you identify autism in individuals who mask?

Yes. Many autistic individuals develop coping mechanisms, such as masking, as a strategy to appear non-autistic. Our clinicians are trained to recognise autism even in individuals who have learned to camouflage their traits.

Do you diagnose other conditions like ADHD?

No. NDAS is dedicated solely to autism diagnosis. However, our clinicians have extensive expertise in ADHD and other neurodevelopmental conditions. If, during your assessment, we believe ADHD or another condition may better explain your experiences, we will recommend seeking a formal assessment.