I never really derived positive benefits from any antidepressant, I'm afraid. Most made me manic, gave me mixed features (which could include anxiety), or rapid cycle. As for Wellbutrin, specifically, the first time I was put on it was the sustained release "SR" version. At that time, I had experienced a long severe depression. I was also on Depakote ER and Invega. The Wellbutrin SR did nothing for that depression (the worst depression of my life). I was eventually taken off and received ECT treatments.
Later down the line, my doctor reluctantly gave me Wellbutrin XR (extended release) on top of Lithium and Geodon (and maybe one other bipolar med). That made me rapid cycle, wildly. Such ultra rapid cycling was never an issue for me before that. I was quickly taken off the Wellbutrin XR. I have not taken an antidepressant since. That was about 10 years ago.