Treatment in the United Kingdom

Hi all. My partner and I have just moved from the US to the UK.
I think my partner has ADHD or a related condition. She was never officially diagnosed, but she has all the symptoms (which she manages pretty well, I have to say).

In the US she was using Adderall to get through her work day. She could get it legally prescribed without an ADHD diagnosis, I still don't understand how - I'm not American myself and I'm not familiar with the private system.
Now we moved to the UK, and so the Adderall pump is dry.

How does it work in the UK?

I've heard that it might take up to 2 years to get an ADHD evaluation through the NHS, and I've heard that Adderall here does not exist - other types of amphetamine are used (as well as Ritalin, which does not work for my partner).
Does anyone have any experience with ADHD here in the UK? Anyone coming from the US or Canada, specifically?