I think to some degree a lot of people with mental illness "fake it" to fit in some of the time. There are a lot of people that misunderstand depression and think it is just feeling sad and can be fixed with a good movie or a piece of cake. I believe you have to have some type of support system for yourself. A group or at least a person that cares about you and you can talk to about how you are feeling.

I pretended to be happy in my teens for a couple of years until I got so depressed I hurt myself. I think if you ignore depression it doesn't do you good. You may have to fake being happy to keep a stable job or for certain events, but you should have someone you can talk to openly.