Psychotherapy works wonders for some people, while being useless for others. The key of it though is whether the person buys into the therapy and works with the therapist. Even the best therapists can help people who aren't open to the experience.

i think more important than the persons willingness is the therapist.
if you have a crummy therapist it doesn't matter how much you believe in it.

True, but like I said, the best therapists can't help people who aren't willing to be helped. Its a relationship.

there are so many factors involved but -obviously- no therapist can do miracles if his/her patient does not open up and/or believes in it. it is a relationship (just like misanthrope86 said)that has to be based on trust. it should go both ways (and, unfortunately, it frequently doesn't).

still undecided...
I Mean I'm not sure That It'll do anything to House, but again, if it did maybe he'll be Happy? idk......

It's not really a simple subject so the answer isn't that simple as well...

Yes. It can be a long process, but I do believe it is effective.
Talking with Dr. Nolan helped House (big time).

Also, Hugh Laurie "spent two years in psychotherapy and credits the experience with changing his life."

Basically what Missy said.
It depends on both, the therapist and the person who is doing the therapy.
If you don't want therapy, then even the best therapist is useless, but if you have to talk to somebody who doesn't take you seriously or in whose presence you simply feel uncomfortable for any reason, than it's not any better.

So yeah, it depends on many things.

It wouldn't work with me, for example. I know that I just need to talk and I can leave, I have no problem talking and letting people believe they know me. But actually let a person in, which is what has to happen for it to work, is another completely different matter.
With House it doesn't work either, he'd sooner run from a problem than to face it, he might talk, he might even open up a bit, but if the problem really troubles him he'll shut down and not say a thing and just do something self-destructive. Doesn't matter what you do to help him. So he'd quit sooner or later, and when he did it was not a bad time to.