My psychopharmacologist told me that the 4-6 week thing is actually a myth. Something about information from early studies being distorted...I didn't quite follow his explanation, but he swore people often feel results in a week or two.
i'm on just aripiprazole and once i was on 10mg it starte dwokring within a couple of weeks. i'v heard anti-depressants are meant to take longer but if not in your case i wouldn't complain :) glad it's helping you.