Most times, people are started out on a fairly low dose, for the purpose of lessening any side effects
. Therefore, at the end of that 4-6 week period, even if you aren't feeling a TON better, it STILL doesn't necessarily mean it is not going to work. At that point, you would regroup with your doc, and discuss the next logical step, which is usually a dosage increase.
Please hang in there...my fingers and toes are crossed that this is going to do the trick.