I've had three. The first one, I saw of my own accord. I actually had to do a fair bit of bonding with a school counselor who convinced my unwilling mom that therapy was something I wanted. He was nice and it was a healing experience, although he often got visibly bored if I didn't bring up something traumatic for a while.
The second was forced on me by my school. Someone on the staff made up some shit about me - a smelly kid who never talked and had no friends - and what a problem child I was. This woman hated me from the beginning, as I was thoroughly unimpressed with her attempts at being a therapist. The other students bought into her vapid, irrelevant psychobabble that she clearly memorized from a college textbook but I didn't. At one point when I was alone with her, she went on an unprovoked diatribe about how I tried too hard to be special and it was sooo obvious from the way I dressed and acted.
For reference, the emo/mallgoth aesthetic was growing in popularity due to the local arrival of a Hot Topic- kids were wearing Tripp clothing, heavy eye makeup, platform shoes, and putting technicolor streaks in their hair. Meanwhile, all of my clothes were drab, dusty, matronly ensembles from the White Stag rack at Wal-Mart. I wore no make-up and my hair was its virgin dark brown. My biggest Hot Topic purchase was a bottle of nail polish because my brother didn't want me wearing the kind of clothes they had there - it was his thing. Yeah I had a "way" about me but what depressed teenager doesn't?
Anyway, in a saga involving an ephebophile English teacher and every adult in the county telling me to shut up and "let it go," this so-called professional told every lie she could to make me look completely detached from reality AND in love with this predatorial HS teacher. Everyone bought it and I had to spend a week in a mental ward for confessing that I wanted to kill him.
The third professional was assigned to me after my big shaming. She was overemotional and completely inconsistent with her advice.
ex: "You should keep going. They say success is the best revenge!"
(a week later) Me: Success is the best revenge.
"You shouldn't use that as a motivator, it's really unhealthy."
TL;DR: visiting with a "professional" can be frustration or disastrous unless it's a decision that you've made yourself.