Yes depression can cause all kinds of confusion and questioning of things. It is a normal symptom to feel detached and less connected to people. Many people have existential questions, like what is the meaning of it all, what is the purpose of life.

I don't buy being addicted to depression. We can certainly get comfortable with it. For example I can be comfortable in it and even be content because I have been in so many of them. They are familiar. I am not always depressed and I know the difference very well. I would much rather not be depressed. Sometimes nothing works and we have to ride it out and learn how to manage it and deal with it. Don't ever give up on treatment though. You never know what is around the corner. Things always change.

Nirvana did the song "Lithium" originally. It did not turn out good for Kurt Cobain. Lots of drugs were involved I believe. Tortured soul. We don't want that to happen. Keep trying.