Here's what you can expect to happen on the day of the assessment and soon after. 

Getting a referral for a diagnostic assessment 

Some diagnostic teams accept self-referrals, but in most areas, you will need a referral from your GP. If you are seeing a different health professional for other reasons (for example, a psychologist if you have depression), you could ask them for a referral instead. Find out what to say to your GP in our pre-diagnosis guide. 

The diagnostic assessment 

Most adults see a psychiatrist, clinical psychologist or a team made up of people from different professions for their diagnosis. Waiting times vary. You can take someone with you when you go for a diagnosis if you like. 

The team or professional might ask you to bring someone with you – someone who knew you as a child, such as one of your parents or an older sibling. This is because they may be able to give important information about your childhood. 

A diagnosis is not a medical examination. You don't need to be examined physically and shouldn't be asked for any samples, such as blood. 

How will they determine that I am autistic? 

The characteristics of autism vary from one person to another, but in order for a diagnosis to be made, you will usually be assessed as having had persistent difficulties with social communication and social interaction and restricted and repetitive patterns of behaviours, activities or interests (this includes sensory differences). These difficulties will have been present since early childhood and will have affected your everyday life.  

There are several diagnostic tools  available, and diagnosticians aren't obliged to use a specific tool. The tool is likely to involve a series of questions about your developmental history from when you were a young child (for example, about language and play.

When will they tell me the result?

The diagnostician will tell you whether or not they think you are autistic. They might do this on the day of the assessment, by phone on a later date, or in a written report that they send to you in the post. 

The report may say that you present with a particular autism profile, such as an Asperger syndrome or demand avoidant profile. Diagnostic reports can be difficult to read and understand in places because of the medical language used. You can call the diagnostician to talk through any parts of the report that you find unclear.  

Find out more about autism profiles, and diagnostic criteria, tools, and manuals. 

Coming to terms with the results

If you are told you are not autistic

Sometimes people are told they aren't autistic, and sometimes they may be given a diagnosis they don't agree with. 

You can seek a second opinion, which either means going back to your GP to explain that you aren't happy with your diagnosis and ask them to refer you elsewhere, or paying for a private assessment. 

If you go for a second assessment, remember that it may reach the same conclusion as your first. 

If you get an autism diagnosis 

If you are diagnosed as autistic, you may have a lot of questions. You might be wondering how you can find out more about your condition, meet other autistic people or access services and support. 

Some people find post-diagnostic support valuable. Some diagnostic teams and professionals offer follow-up services after diagnosis and might be able to answer your questions and point you towards support services. However, not all do this. 

Support does not automatically follow diagnosis, but having a formal diagnosis does mean that you are more likely to be able to access services and claim any benefits you are entitled to. Not everyone feels they need further support – for some people, simply getting a diagnosis is enough.

What next? 

• Spectrum Live is our interactive live stream event that you can access for free, from the comfort of your own home. Watch an episode of Spectrum Live about autism diagnosis. 

• Read more about diagnostic criteria and tools

• Read our information for autistic adults - after diagnosis

• Find out more about what help and support is available

• Join our online community and connect with other autistic adults

• Read more about autism

• Subscribe to the Spectrum, a free publication by and for autistic people 

• Become a member to receive Your Autism magazine, our quarterly magazine for everybody with a connection to autism.