So around a couple of years ago I suspected I was autistic. I'm from the UK so the process may be different for a lot of you.
The first step that I did was take some tests online, these aren't absolute obviously and should be taken with a grain of salt, but I spotted patterns between the results, which solidified my suspicions of autism.
These are the tests I took:
The Aspie Quiz is a self-administered questionnaire to measure the degree to which adults with average intelligence show autistic traits. We discuss its scoring, its validity, and more.
embrace-autism.com
The Autism Spectrum Quotient (AQ) is a self-administered questionnaire used to measure the degree to which adults show autistic traits.
embrace-autism.com
The RAADSāR is a questionnaire designed to assist clinicians with the diagnosis of autistic adults who often āescape diagnosisā due to a subclinical level presentation.
embrace-autism.com
The CAT-Q is a self-report measure of social camouflaging behaviors in adults, used to identify camouflaging behaviors in autistic people.
embrace-autism.com
After taking those tests, I read through the ICD 11 (the diagnostic manual used to diagnose autism and other things, at least here in the UK). I looked through the criteria for autism, but also other disorders with overlapping symptoms, like OCD or GAD. I went through each one, one by one ruling each diagnosis out. I realised autism was the most likely explanation for my symptoms.
Here's a link to it:
After all of that I went to CAHMS, about it as I was still a minor. They were very reluctant to refer me for an assessment as they deemed me "too smart" to be autistic. After a lot of arguing they finally allowed me to fill in paperwork for a referral.
The first set of questionnaires you fill out, is in two sections. One for you and your family to fill out, and the other for your place of work or school to fill out. The questions relate to your daily functioning, and developmental history. This is then sent off to the assessment services, and scored. Depending on how high the score is they will decide whether to assess you or not.
Mine came back as conflicting because the paperwork my family filled out came back with a higher score then the one my school filled out (essentially I'm smart schoolwise so they doubted I was autistic). Due to this, they put it under review and then decided to put me through for an assessment.
The waiting list was years long, I waited 2 years before being given an assessment. I was meant to wait longer, but after multiple ctb attempts they were essentially forced to do it.
The assessment consists of more paperwork and then 2 interviews.
The paperwork consists of questions about developmental history, medical conditions in the family, and childhood development and behaviours.
The first interview consists of you alone, and two psychologists. They make you do a lot of different tasks to determine how your symptoms present in person. Some of the tasks they made me do consisted of: Puzzles, creating stories out of pictures and inanimate objects, engaging in small talk, acting out day to day tasks like brushing your teeth, and just overall observing your behaviours and mannerisms.
The second interview is with your parents or family member. They go in depth about how you were as a baby, and in your younger years. They mostly talk about developmental milestones, how you played as a child, ect...
After all of that they write up a report and consult more people and ultimately decide if you meet the criteria or not, this takes around 3 weeks. They will then send over a diagnostic report, with all of their observations, and there you are you're diagnosed!
Post diagnostic support at least where I live in the UK, is non existent. I have asked for support and there is nothing. You are essentially given a diagnosis and booted out the door.
Anyways, sorry for the essay but that's how the diagnostic process went for me, I hope this is helpful for you.