Oh my gosh I was going to make this thread and you beat me to it! Damn
Anyway I've had some good and some bad experiences.
In terms of diagnosis, they don't like to give you one. Most of the UK mental health services are actually reluctant to give diagnoses unless they view them as entirely necessary, because they believe that it's more important to treat individual symptoms than a diagnosis - which I agree with, partly. Not 100%, but I can see their point.
CAMHS also has additional reasons for not wanting to diagnose, including the fact that disorders diagnosed in adolescence can then stick with them for their whole life, giving people a stigmatised label that they may have "outgrown" (whether naturally, because behaviors and personalities change, or through therapy), which can affect all sorts of treatments in the future.
There's a lot of reasons CAMHS doesn't like to diagnose and I won't go into all of them because it'd take forever, I don't necessarily agree with all the reasons either (or most of them).
But basically,
TL;DR, CAMHS very seldom diagnose.
Anyway, onto my actual EXPERIENCE...
It's been super mixed. It was bad, terrible, good, now it's bad again.
I was referred by my GP for anxiety attacks I was having in school. Probably not a detailed referral, but hey - anxiety - CAMHS can do stuff about that!
But they declined the referral because that wasn't "their business" and it was up to the school to deal with, and told me I could only get into CAMHS for school reasons if I got referred by an educational psychologist.
They hadn't even met me at this point, I need to say. They'd just read a referral made by my GP during a five minute appointment.
Not only that, but I had to wait eight months just to be told that they didn't accept me, because instead of telling us - the family, they told the school.
Ok so fast forward a bit, it's my first appointment with the nurse. A conversation goes like this - it's January 2014 at the time, just keep that in mind. (vague
suicide TW, nothing too explicit):
Nurse: Have you ever tried to kill yourself?
Me: Yes, in December. Please don't tell my mum she's really not good about this stuff.
Nurse: Don't worry I won't - this is confidential!
A week later, a letter comes through. It's addressed to my mother.
It says, in detail, most of what I talked to her about. Including this gem: "Had experienced suicidal thoughts and made an attempt 18 months ago"
18? Where did I say that?
Anyway I could say more but this is super long, I definitely have some great CAMHS gems though.