It depends, you might get disability support. In Europe of course. But if you've already got that there is no added benefit there additionally.
However, it might be great to know and get the world off your back even if it's only or maybe especially for yourself. Have a look at the comic 'hidden differences', I thought it shows that point quite well.
I'd love to get the diagnosis, but sadly in my (EU) country it's almost impossible as an adult and I already paid money myself for this. So I am happy just knowing.