Gp referred us. Disgnosis was quite quick with questionnaire for us to fill in, couple of appointments with pead where they observed ds, qb test and evidence from the school - wouldn't start process until he was 6. I insisted on an ecg before starting meds. Thye worked very quickly but side effects were bad first few wks. His meds have stopped working and iv forgetten how manic he can be
I think that depends on the area, for us it's part of the children's hospital. When you go to the GP they'll probably ask you about school as well as home behaviour so if you can have some details from the teacher that can be helpful.
We've definitely seen the benefits in school, especially when moving up a year to a new teacher and now that we're getting ready for secondary. It gives his teacher a chance to hit the ground running in Sept, knowing how best to help him. Meds have also had a massive benefit and helped identify other learning issues (dyslexia and sensory issues).
At home it's helped us understand what's ADHD and what's him just being ten, and how to respond and manage situations for the best.