I don't think its easy to get a diagnosis at all, in fact Id say it was like climbing a bloody great mountain, seeing the top but getting pushed back to the bottom again before having a chance to get there.
I started vocalising concerns when ds1 was about 18months, started seeing paed when ds was 3 and have seen many including ed psych, camhs and various others over the last few years. the hospital saw him from 3, but refused to do anything till he was 7.
the only real "test" for sn he has had was a conners scale (what a piece of useless crap!) and the hospital took bloods, said he had a insignificant abnormality on his X chromosome, were going to test me and ds dad to see if we carried the abnormal one or wether it started in ds1.....those blood tests never happened so now at 10 we are still very much where we were 6 yrs ago.
Ive given up trying to get help tbh, blatently Im seen as a crap parent(ignoring the fact my other dcs are perfectly normal, happy compliant children with no ishoos whatsoever!) I just cant continue the fight with the professionals, I found it exhausting.
It doesn't bother me too much as I get a lot of respite during hols etc which is funded from his school, but If he ever did anything so serious it put my other children at risk though, he would be taking a swift trip to SS office and I will be leaving him there for them to deal with- Ive spent years trying to get him help with no avail so if it gets too bad, someone else will have to take on the fight because I wont.
I don't believe many parents actually have a diagnosis of things like adhd- a lot of the time I think its parents saying that's what there child has without any formal diagnosis, why someone would want to give their child a false made up diagnosis is beyond me, but Im guessing its a bit like Munchausen by proxy.