The majority of this information applies to the Norfolk, UK pathway and assessment process for a more general overview you can visit the National Autistic Society
Autism Service Norfolk
In Norfolk, the adult diagnostic service is provided by Autism Service Norfolk.
Autism Service Norfolk is an NHS employed service funded by Norfolk County Council. It provides a gateway for the diagnosis of adults 18+ with suspected Autism without a learning disability. It is also able to provide some pre and post-diagnostic support around the diagnosis. Autism service Norfolk does not provide any mental health or social care support or management.
Visit their page here
Getting a Diagnosis?
The first port of call should be your GP. Explain o them the difficulties you are having and why you think it may be Autism. it is best to take along a family member or friend who is aware of your difficulties and can mention anything that you forget or can't remember.
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. You could ask to see another GP at the surgery.
The characteristics of autism vary from one person to another, but in order for a diagnosis to be made, a person 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 behaviour), since early childhood, to the extent that these 'limit and impair everyday functioning'.
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, play and cognition).
The team will usually let you know on the day if they think you may have Autism or not, but they may send a report or schedule a following up phone call to discuss the results of your tests/assessments.
For more information on the diagnostic criteria and tools that can be used please click here