For mood stabilization for acute Bipolar Type 1 episodes 400 up to 800 is the range, according to my psychiatrist....occasionally 300 mg for some, but more for BP2 hypomania/depressive prevention. AP effects start to take place at 600 mg, but sometimes less, depending on the person. Anything lower than 200 mg is typically for sleep. 450 is a moderate dose in general, but some would say it is actually less sedating than lower doses (Seroquel is weird like that). I still find it sedating though...just takes longer to get to bed.

I was on 600 mg for a while and recently lowered to 400 mg, because I was sick of feeling even more irritable and had some scary side effects, such as occasionally having problems breathing at night. 400 mg is working out better, now that the higher dose wiped out my state of "acute mania". It's a good mainenance dose. I might need to go taper up again at times, when there's signs of flare ups/onset of episodes.

I developed somewhat of a tolerance getting to sleep with Seroquel, but only in the sense that it takes longer to kick in. Once it does though, it still knocks me out. That effect will usually happen a few hours after taking it, where it used to be in a shorter time frame. I have to take it much earlier than I used to, so that I don't feel like crap and dizzy before work. I'm not feeling as much of a hangover on 400 though. 600 mg sometimes would make my blood pressure drop and difficulties driving.