SOLVED. YA School for kids with ESP disguised as mental illness [s]

[Benjamin]

Probably published in the 90's. A boy goes to a boarding school for boys and slowly realizes all of his classmates, except him, have psychic powers but don't realize it.

One boy is thought to throw stuff for no reason, but it turns out he has telekinesis.

He tries to convince his friend that he has ESP by having him guess cards. The friend gets every card wrong, which the boy uses as proof he has ESP and is trying to hide it (because random guessing would result in some correct cards).

They find a way to escape at night (through a tunnel, maybe?) and try to do some superhero stuff, and sneak back into school during the day.

His friends finally convince him that he has a superpower, too.

All of their powers are misdiagnosed as mental illness or behavioral issues, which is why they have been sent to this school (maybe a juvenile detention facility?)

[Juels]

Hidden Talents and True Talents by David Lubar?

[Benjamin]

Hidden Talents be it! Gracias.

[Juels]

You're welcome.

[Lobstergirl, au gratin]

This is a popular book. Requested 7 times now.