Yes, I had a problem with generic Wellbutrin SR. Both were bupropion SR, but the one worked for me & had been for several years. Then I switched pharmacies & the new pharmacy used a different brand. I noticed a change in my moods almost immediately & asked the pharmacist if therre could be a difference between the 2 & he said possibly. I switched back to the first one & leveled out again. It is now on my records to only fill my scripts with the one brand. This is also true with another medication I take, so sometimes it's worth asking if there is a different generic. Or if you were getting the Brand name then switched to a generic & notice a change, that could be the issue.