The sleep paralysis thing...this is why I asked at the beginning of this thread if you meant a dream dream or hovering between waking and sleeping states--because it's during the latter that sleep paralysis will take place, either upon going down to sleep or coming out of it, or even both.
I deal with delayed sleep phase syndrome and the sleep paralysis thing. Both the delayed sleep phase and the sleep paralysis is part of what helped my ex-husband get away with slowly and carefully raping me in my sleep, without waking me--or without my being able to react, even when I woke up to what was happening.
I would also sometimes go right back to sleep again after waking up to the knowledge of it, because of the pure exhaustion of trying to keep a regular day schedule with this night-oriented body clock. [Like chronic third shift work fatigue--only for ME, the first shift (day time) is actually what feels like 'third.']
We talked about it one time--ostensibly after he had stopped doing this for some time--and he told me that the number of times he had actually done it and gotten away with it was actually higher than the number of times I was guessing based on waking recollections.
SICK, SICK, SICK !!!!!!!!!!! --Sorry....I know it's a bit off topic...............but I want people out there to understand and know that this horrible stuff DOES happen, and to be able to understand a little bit about how it IS possible, since so many have the mistaken belief that a woman cannot be raped in her sleep.
So...yes...if you're talking about a recurring dream, that's one thing (PTSD-related, most likely)...but if you're talking about conscious wake-sleep hover states, that's a sleep disorder. Sorry I didn't say anything on it earlier...I was too exhausted and needing to go down for a bit... (Go figure!)
Edit: And BTW, there was no chemical substance of any kind involved, not even sleeping pills. Just plain, pure exhaustion.