I was diagnosed in 1983 of being Bipolar II - I was 27 y.o. at the time and it was after about 8 years of swinging.  I have been on 900 mg per day of Lithium since back then (except for the times that I quit taking the lithium and then went manic and then depressedd and started to take the Lithium again, etc.... - long story).  My 28 y.o. daughter went completely manic three years ago (Bipolar I) and was hospitalized in a psychiatric hospital for 9 weeks.  They tried all kinds of medication on her and it seemed like the best combination was 1200 mg of Lithium per day and also Seroquel (don't know the dosage of the Seroquel but I know it was a high dosage of it).  She was on this dosage of both medication for about 2 years which left her very sluggish, especially in the mornings.  She was actually having trouble functionning like a normal person.  In the last year, her psychiatrist started reducing the Seroquel very little at a time.  What a difference this has made.  She can function better - is working and looking after her young daughter.  The Dr.'s aim is to get her off the Seroquel very, very slowly and then just have her on Lithium which has worked very well for me in the past 20 some years.

Getting back to you, probably if it is done probably and by a Dr. who knows what he/she is doing and also monitors you very closely, you may be able to get off the Seroquel.  I  hope that you are not completely weened out and and not have another med for a back up.  Do consult with your doctor - and like I said make sure that he knows what he is doing because otherwise it could disastrous if not monitored closely.

Good luck and all the best.

Monique