The diagnostic process is applied differently by various psychologists. When I was diagnosed it was a ~6 hour process done in a single day, basically an entire day of assessment with a couple of breaks. But I know people who have been diagnosed in as little as 30 mins.
The diagnostic process may vary depending on the reason. When assessing a child who is eligible for government benefits they may be more careful to do an assessment that can't be questioned - or they might just rush it through on the basis of "this child needs the government assistance so I'll make sure they get it even if the DSM doesn't agree" (seriously).
Autism is genetic, so in cases where someone's close relatives have been diagnosed the process will be a lot quicker.
A thorough diagnosis depends on knowledge of the person when they were young. If your parents have died, are estranged from you, or have mental health problems that preclude them assisting with the assessment then this will make things more difficult.
One thing that's useful for the psychologist is knowledge of the way you think. If you can give examples of how you thought about situations you were in then it can really help.
The diagnostic process may vary depending on the reason. When assessing a child who is eligible for government benefits they may be more careful to do an assessment that can't be questioned - or they might just rush it through on the basis of "this child needs the government assistance so I'll make sure they get it even if the DSM doesn't agree" (seriously).
Autism is genetic, so in cases where someone's close relatives have been diagnosed the process will be a lot quicker.
A thorough diagnosis depends on knowledge of the person when they were young. If your parents have died, are estranged from you, or have mental health problems that preclude them assisting with the assessment then this will make things more difficult.
One thing that's useful for the psychologist is knowledge of the way you think. If you can give examples of how you thought about situations you were in then it can really help.