I see a therapist because it helps to talk about my concerns with someone that is impartial. She also helps me see things from a different perspective when I get "tunnel vision". For me managing the bipolar effectively is a combo of things and therapy is one of them.

I have some very close friendships, but I don't want to burn them out with endless talking about issues that will come up again and again i.e. depression, childhood abuse. My friends are also not equipped to help me work through those issues. Yes they can be great listeners, but I need to work through those feelings.