Depersonalization - state in which one's thoughts and feelings seem unreal or not to belong to oneself, or in which one loses all sense of identity

Derealization - a feeling that one's surroundings are not real, especially as a symptom of mental disturbance

Dissociation - separation of normally related mental processes, resulting in one group functioning independently from the rest, leading in extreme cases to disorders such as multiple personality

(Definitions from Google)

I am diagnosed as Schizoaffective Bipolar type, and Dissociative Identity Disorder, among other things.

So, sometimes these can look similar.

I have these "stories" as I call them, in my head, that are not related to the DID at all. They are more, idk, comforting, like what I wish life had been... sometimes, tho, they begin to feel more real than actual reality. To me, that is part of psychosis.

Whereas, the dissociation is my outside functioning is "dissociated" from my inside functioning. To the outside world, I am normal, going about my day with ease. However, "I" have no idea what is going on. One of my insiders is usually in control during these times. This is on the extreme end tho. On a more normal end of dissociation is something like getting off work, getting in your car, and then you are home, but don't remember the drive. You've done it so many times, that you went on "autopilot" and got lost in your thoughts. It can be scary, but not necessarily clinical. It happens to most people.

I don't know if this helps, my brain is a little weird right now, been struggling and having a hard time lately... ask anything and I can try to answer...