Seroquel was a huge failure for me. Some people really like it because they find it helps with their mood, but as others mentioned, it carries the risk of causing weight gain and drowsiness. (For me, though, there was no weight gain... BECAUSE I WAS SLEEPING THE WHOLE TIME!)

I used to take Seroquel PRN (25mg) with Abilify to make me sleep if I was getting minimal sleep. However, when Abilify pooped out on me, we moved onto Seroquel XR. What a mistake that was!

Seroquel XR (at 150mg) wasn't helping with my psychosis or mania, so we decided to bump it up to 200mg. Unfortunately, the increased dose triggered a VERY nasty depressive episode in me, one of the worst I've ever experienced in my life. At first, I thought it was a crash from an elevated mood state to a depressed mood state, so we increased the dose to either 250mg or 300mg to combat the depression (can't remember which dose because it's been a while). Then my depression got even WORSE. At that point, I demanded to be taken off of it. And, to no one's surprise, the depression went away very quickly after stopping it!

But anyway, YMMV with this med. I don't think most people have the depression problem that I had. I haven't found anyone else who's had this problem... but the risk is there, and even some websites warn you about it triggering or increasing depression. So, if you increase your dose at some point and you find that your depression is worsening, it's very possible that Seroquel XR (or regular Seroquel) is causing depression.