does wellbutrin stop working?

h,i i have been taking 300 mg of wellbutrin for about 2 years but recently it does not seem to have been working. actually i take the generic bupropion  sr  could this make a difference? i hesitate to switch to another med  for fear of weight  gain and loss of  sex drive, both of which would also lead to depression. i have been feeling really down. not that i was "super happy" but the "wellbutrin "  did take the edge off. i had been on a few others imprine and some others i don't remember, but the wellbutrin while not making me feel super up at least made me feel normal and not like **** like most of the others i have tried. any help would be appreciated. thanks

[Roger Gould, M.D.]

As you described, the medication takes the edge off...but if you are becoming more depressed maybe you ought to look at the source of depression, and try to resolve it through psychotherapy, rather than suppress it with medications.  Your other alternative is to ask your doctor if he or she is willing to increase your dose temporarily.