hi. maybe a paradoxical effect. at low doses, seroquel is basically a densely sedating antihistamine. maybe it has something to do with the histamine receptors? some people get oddly giddy from sedating antihistamines, so...yeah. there's that.

drug-drug interaction, maybe? I don't know, of course. maybe you could try running one of those drug interactions checkers on what you're taking and see what comes up?