" diagnosis during childhood so if you're 30 or 40 you might have no chance "
Huh? You don't have to be tested as-a-child, you don't have to call up your fourth grade teacher. You can self report your subjective experience.
"Did you have these problems as a child? Have you always had trouble doing your homework? Did stressing out about homework enable you to do the homework?"
They ask the question a few different ways typically.
I get it, perhaps it is different in your area, but I get the impression that an adult ADHD diagnosis is far from impossible.
Only recently in aus did an adult diagnosis get support from the government PBS scheme. And even then it's because they're letting retroactive childhood diagnoses be considered for the subsidised medication options.
In some countries it's almost impossible (I don't have any direct experience but I've heard tale that in e.g. aus/nz, east asia, south asia, etc people give up before getting diagnosed often), and my understanding is that in Europe it's virtually unheard of to have an adult diagnosis.
In the US, at least, it ranges from difficult to straightforward, but that's not true everywhere
Europe here. I have several friends that got diagnosed with ADHD as adults.
If you try to do it through the public system it's very difficult to even get an appointment because there's months long waiting lists. Basically if you have a job and function somewhat OK in normal life you won't be diagnosed in the public system. If you do get through it can be a long process where they want to interview your parents etc to determine if you had symptoms as a child. But you can also get a diagnosis through private practitioners and some of them function almost like diagnosis mills. A couple of video interviews and tests and you are done.
In NZ it's easy, and some GPs can do it as of earlier this year.
IDK I'm just going by a friend moving there and not being able to get any of her existing medication prescribed, even though she's been diagnosed for literally 40 years.