Used to work for a Department of Mental Health; asked my boss (a psychologist) about talking to one's self. He said it's okay to talk to your self (almost everyone does it); it's also okay to answer yourself. The thing is -- do you REALIZE that's what you're doing? Do you KNOW that you're only talking to yourself? If you do, you're probably okay. People who are delusional or temporarily confused actually think someone else is there.
No. Talking to yourself has nothing to do with depression. I know many people who talk to themselves and they are SURELY not depressed. For example, when my grandfather is out working in the garage, yes, he talks to himself. Depression? No.
No, not really. A lot of people just do it because it helps them think. But if you have whole conversations with yourself and talk like you're two different people...that's a different story. I hope I helped!
Its very healthy to talk to ones self. I do it for reassurance. Sometimes it helps me get motivated. Sometimes it even helps to answer your own questions about life. Your not crazy nor does it mean you have depression.