I think it's difficult to say in this situation. I'm bipolar, not schizophrenic as far as I can tell but my internal monologue talks in all sorts of ways. It is perfectly normal for a person to talk to themselves it's a learning tool really. But the question is can you really hear them or is it a thought. Is it possible that when you are depressed you simply are likely to believe that you percieve the worst case scenario is the truth. When I am depressed I sometimes have delusionss that I am losing my mind when there is little evidence.