At least in my country the autism test seems pretty thorough and I would expect it to be pretty consistent. There are multiple tests you take where you answer questions and get numeric scores. Then multiple interviews with different people. In my case, first a school nurse, then a nurse specialized on mental health, then a psychiatrist, then a psychologist. They also interview parents, look through school records and teacher feedback and medical records since childhood.

After diagnosis I was also put in a group with 5 other newly diagnosed autistics and 2 occupational therapists where we talked about what autism is, how it impacts us and how all the traits apply to us. There were six 90 minute meetings to discuss and make sure we all properly understand and are comfortable with our diagnosis and to adress any potential concerns or questions about why we were diagnosed.

The issue is of course that there is no clear blood test or anything you can take that 100% guarantees correct diagnosis. With autism diagnosis there is always some room of interpretation that is up to the professional. But I think that the fact that so many professionals are involved in the process might mitigate inaccuracy to a certain degree

That makes a lot of sense.

There are lots of conditions that don't come with clear lab results as bench marks - even MS wasn't considered a physiological disease for a while (as compared to psychosomatic/psychological) because physicians couldn't identify biological markers for ages. So it's really important to me that it be accepted/understood that just because there is no lab test doesn't mean a condition isn't real, doesn't cause distress, and doesn't require accommodation/assistance.

And that in turn means that we must insist that just because some conditions require clinicians' interpretation, we're not going to pretend that fictitious and entirely subjective 'conditions' like "being born in the wrong body" are real. Among the many reasons TIPs make me angry is that by borrowing the language of disability, they cheapen it, and when people realize they're full of shit, they might conclude that people with autism/depression/MS/ME are also full of shit.