Man in blue shirtGetting a diagnosis of autism (including Asperger syndrome) can be a really positive thing. A lot of people say their diagnosis has helped them to understand why they have difficulties with some things and why they are especially good at some things.

Having a diagnosis also means you can get easier access to support and benefits. However, the process of getting a diagnosis can be difficult for adults. This guide aims to help.

How to get a diagnosis

Some diagnostic teams accept self referrals. You can check the Autism Services Directory to find out if you can refer yourself to your local team. However in most areas, you will need a referral from your GP.

Step 1: speak to your GP


In most areas, you should visit your GP and ask for a referral to a psychiatrist or clinical psychologist, preferably one with experience of diagnosing autism. Make sure your diagnosis is the only thing you are seeing your GP about. If you try to mention it during a consultation about another subject, your GP may not address it fully.


Your GP needs a reason to refer you for diagnosis, so you will have to explain why you think you could have autism, and how a diagnosis would benefit you. If you think you might want help with this, ask someone you know to come with you.

You might say that you have been reading about autism, or that you've been in touch with The National Autistic Society (NAS). You think that you experience some of the difficulties that people with autism can face, and you would like to seek a formal diagnosis to be sure.

Below, we summarise the main difficulties that people with autism experience - you can discuss these with your GP. Not all GPs will have an in-depth knowledge of autism, so it's important to explain things as clearly as you can. We have written a helpful guide for GPs.

If you are seeing a different health professional for other reasons (for example, a psychologist if you have depression) you might prefer to ask them for a referral instead.

Step 2: presenting your case

Autism is characterised by three main areas of difficulty and if you have autism, you'll be affected in some way in each of these areas. However, everyone with autism is different and no one person will have all of the traits listed below. Try to give your GP one good example from each of the three main areas of difficulty.

The three main areas of difficulty

Social communication
People with autism sometimes find it difficult to express themselves emotionally and socially. To give some examples, you may:

  • have difficulty understanding other people’s gestures, facial expressions or tone of voice
  • be unsure about when to start or end a conversation, or how to choose topics to talk about
  • talk or read very fluently but not fully understand the meaning of some of the more complex words and phrases you use
  • be very literal and sometimes struggle with jokes, metaphors, sarcasm or common turns of phrase, such as 'She nearly bit my head off'.


Social interaction
Plenty of people with autism want to be sociable and make friends, but often say they're unsure how to go about this. Socialising can be difficult and may cause considerable anxiety. To give some examples, you may:

  • find it hard to make and maintain friendships
  • find other people unpredictable or confusing
  • not always understand the unwritten 'social rules' that other people just seem to know. How close do you stand to another person? How do you know what's an appropriate topic of conversation?
  • be unsure how to behave in different social situations, and worry about getting things wrong.


Social imagination
People with autism have difficulty with social imagination. To give some examples, you may:

  • find it hard to understand or interpret other people's thoughts, feelings or actions - and therefore to understand their intentions or to predict what they're going to do next
  • not always be comfortable with the idea of change, and prefer to stick to a routine
  • enjoy carrying out particular activities, or learning about certain topics, which as well as being enjoyable you may find really beneficial. Perhaps they help you to relax, or to deal with anxiety.


Many people with autism are imaginative (for example, they are accomplished writers, artists and musicians). If you're quite creative, this shouldn't automatically be taken as a sign that you do not have autism.

Related characteristics and conditions

As well as the three main areas of difficulty, you may find you have some of the following characteristics or conditions, which are quite common in people with autism. You should tell your GP about these, too.

Sensory difficulties
Sensory difficulties can affect all seven senses: sight, sound, smell, touch, taste, balance ('vestibular') and body awareness ('proprioception').

You might find that you are either over-sensitive or under-sensitive to different stimuli. For example, you might be averse to bright lights, loud noises, some smells, particular food textures or the feeling of certain materials. Any of these could cause anxiety, possibly even pain.

You may also find it harder to use your balance and body awareness systems, which let us know how we're moving and where our bodies are in space. So you might find it harder to navigate rooms avoiding obstructions, or go up and down stairs. You might also find that repetitive activities such as rocking, hand-flapping and spinning (which many people with autism do) help your balance and posture.

Love of routines
In an effort to make the world less confusing, you may have rules and rituals (ways of doing things) that you insist upon. You might also have a strong preference for routine, and find it difficult to cope with change if you haven't been able to prepare for it in advance. For example, an unexpected delay to your journey to or from work might make you feel anxious or upset.

Special interests
People with autism may develop an intense interest in a particular subject or activity. Interests can change over time or be lifelong. Practically everyone has interests or hobbies but you may find that your interests are very strong, and that possibly you aren't especially interested in learning or talking about other things. 

Mental health difficulties
Some of the more common mental health difficulties that people with autism can experience are anxiety and depression. A related issue is self-injurious behaviour, such as hitting or cutting yourself. Mental health difficulties can be addressed, and often more successfully if professionals know that a person also has autism, so it's important to discuss this with your GP.

Other conditions
Some people with autism also have learning disabilities, or specific learning difficulties such as dyslexia. Other people have conditions such as epilepsy. You may not have any of these conditions but if you do, it's helpful to describe them to support your case.

The law and guidelines


The process of diagnosis will vary depending on where you live.

There isn’t one standard way for an assessment to be carried out, but there are guidelines that professionals should be following such as those issued by the National Institute for Health and Clinical Excellence (NICE). NICE Clinical Guidelines apply in England and Wales but may also be taken up in Northern Ireland after being reviewed. NICE Clinical guidelines have no formal status in Scotland.

Further guidelines for each country are described below. It may be worth letting your GP know that you are aware of the strategies, laws and guidelines relevant to the country you live in. If your GP does not want to refer you for an assessment you could show them the information about these to challenge their decision.


  • England. The Autism Act (2009) led to the government producing statutory guidance for adults with autism, which is called the autism strategy (England only), published in December 2010. The autism strategy says that local authorities in England must have a clear pathway of diagnosis for adults, meaning that you should be able to have a diagnostic assessment and your GP or local authority should be able to tell you how you can get this assessment.

  • Northern Ireland. The Northern Ireland Autism Act (2011) says that a strategy should be published to ensure that the needs of people with autism and their families are met throughout their whole lives. The Health and Social Care Boards Regional Autism Spectrum Disorder Network’s Adult Care Pathway (2013) provides guidance on autism assessment, diagnosis, and intervention and says that after screening, adults should be referred to a specialist autism multi-disciplinary team.
  • Scotland. The Scottish Strategy for Autism (2011) includes goals for improving diagnosis and states that for adults, getting a good quality diagnosis is the key foundation that will lead them to understanding their condition and for the best support to be made available to them.
  • Wales. Autistic Spectrum Disorder (ASD) Action Plan for Wales (2008) specified a care pathway for adults. This says that your GP should refer you for a local multi-disciplinary assessment by a team with knowledge and expertise in the assessment of adults and Asperger syndrome.

Step 3: getting a referral

If your GP agrees to refer you, we recommend that you tell them about local services that have experience of diagnosing autism.

As an adult seeking a diagnosis, we think it's really important that you are referred to the right person, or service, first time round. You are more likely to be accurately assessed, and will avoid having to go back to your GP to ask for a second referral. Be aware, though, that it can sometimes be hard to find a service or professional with experience of diagnosing autism in adults. 

You can find diagnostic services in your area by searching the Autism Services Directory (print details out and take them with you), or by contacting our Autism Helpline on 0808 800 4104.

Once you have been referred, there is no more involvement from your GP.


You are most likely to be referred to a diagnostic service within your local Clinical Commissioning Group area (in England), your Health Board area (in Scotland), your Local Health Board area (in Wales), or your Health and Social Care Trust area (in Northern Ireland). You can be referred to a service outside your area, but as this costs more, your local NHS commissioning body might question why you need to go there, or whether you really need a diagnosis. Private diagnosis is always an option, if you can pay for one, but you may occasionally find that local service providers (for example, social services) will not accept private diagnoses and will insist upon you having an NHS diagnosis, too.


Most adults see a psychiatrist or a clinical psychologist, although this does vary. Waiting times also vary.


What if my GP does not refer me?

If your GP decides not to refer you for a diagnosis, ask for the reason why. If you don't feel comfortable discussing their decision then and there, you can ask for a second appointment to talk it through.

If you wish to complain about any aspect of referral or diagnosis, there is a complaints procedure that you can follow.

What next?

See Diagnosis: what to expect for an idea of what might happen when you go for a diagnosis.


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