Some medications have caused me truly horrific nightmares- one was Effexor.

One horrific nightmare I had on that I dreamed that beings from another dimension were invaliding my mind through the "spaces" in my thoughts, my "speculative ideas" had opened a window through which they could attack me. They were there, always there and waiting for my death. There purpose was to torture me and it was my destiny to be taken by them and kept in horrific torment for all eternity. I mean that is only a brief overall of the dream.

I woke up terrified, and feeling disorientated. I walked around the house and the ideas were still in my head, I was terrified they were coming for me. I did not feel real, even though I was awake, I felt totally disconnected from my surroundings, as though I did not know what I was doing, I felt confused.

It took being awake for a while for these thoughts to go away.

I had various, extremely intense 'hallucinogenic" nightmares on the stuff, visually very intense psychedelic scenery but of a horrific nature. I felt like I was going insane.

I went off that medication, and have never experienced the same things since.