I can answer my own question now. Seroquel makes me feel a bit sleepy initially but it wore off after a few weeks. I get the occasional day where I feel like waves of lethargy crash over me, so much so I need to rest for an hour. I don't feel like a zombie or anything, if anything my mind is clearer. The constant churning of thoughts is fading away, and my two little chattering chums are less intrusive now. On a bit of a downer I seem to hear a third voice, it sounds like it hides behind the others, lately it is becoming more noticeable. My psychiatrist wants to up my dose from 200 mg to 300 mg, I put it off for a while, now having weighed up the pros and cons I will up the dose next time I see him. It has also had a marked effect on my depression in a way the venlafaxine never did. The fly in the ointment is I now believe I am surrounded by angels. Why, and good or bad I have no idea yet.