We're just starting the process with my DS, he's 13. His mental health is terrible because he can't sleep as he can't switch off his brain. I've always thought there was something but as he's well behaved and it didn't seem to bother him I didn't push for an assessment, then hormones kicked in and it was like he changed overnight. The last 18 months have been horrendous! He's very bright, no problems at school, except his attendance is poor because of no sleep and poor mental health.
I spoke to school and they thought Autism rather than ADHD but they supported the referral to CAMHS. CAMHS knocked back the autism referral as not enough evidence but accepted the ADHD one. (I'm beginning to think Autism too, there's a family history of both.)
We've since gone via Right to Choose as for his sake we can't afford to wait the 4 years for an assessment when medication could be life changing for him.
If you go on the ADHD UK website there's a list of providers. You have to look through to see who are currently taking referrals for children and how long the waits are. A lot are online so they don't need to be local to you.
I thought it was going to be really difficult to refer but I just had to complete a SNAP assessment form (took 5 minutes) then download the letter they provide, put in DS's name, my name, GP practice and ask the GP to send it off.
We've got with the Owl Centre who might not be in the ADHD UK website as they've only just been approved for Right to Choose.
I do get why some people don't get a diagnosis. It can stop you joining the army (not a bad thing in my eyes, and DS wouldn't want to anyway) and it can cause problems sometimes if you want to emigrate, but that's generally only if you're going to be a burden on the state and cost them money. But DS needs help now so it's not something I deliberate long about.