Wellbutrin is an interesting Rx. As an antidepressant it is in a class of it's own. It is unique in that rather than acting on serotoninergic neurotransmission, as the SSRI's do, it is actually an SDRI (selective dopamine reuptake inhibitor) that also has some effect on the noradrenergic systems as well.
Mikeford is correct, it does have a low side-effect profile compared to many of the SSRI's. For example you won't experience any of the anti-cholinergic or anti-histiminergic sidefx that antidepressants are famous for like dry mouth, sedation/drowsiness, constipation etc. Unlike the SSRI/SSNI's it is actually somewhat stimulating, so may give you a bit of energy (which is very hard to come by when your really depressed). Best of all it doesn't kill your libido, or cause weight gain -- in fact the average person actually loses a few pounds on it.
Meta-analysis has shown it to be approximately equal in effectiveness compared to the SSRI's in treating depression, but not nearly as effective at treating anxiety. In fact it can aggravate anxiety for some (it did me unfortunately). Also, because it does NOT act on or interfere with serotonin, it is often prescribed along with SSRI's for those that do not achieve full remission of their depressive symptoms from their SSRI alone.
The big drawback with Wellbutrin is the potential for it to cause seizures. The risk is dose related, and more likely to occur in those taking doses of <650mg/daily (the typical therapeutic dose range is 150-300mg). However, even then the risk is still relatively low (2-3%). Consuming alcohol while taking Wellbutrin dramatically increases chances of seizure, so this isn't a good Rx if you are a fan of the bottle.
Interestingly enough because of it's simultaneous affinity for the nicotonic receptor sites in the brain, it is helpful for those trying to quit smoking. In fact, it is the active ingredient in Zyban the smoking cessation Rx.
Here's to better living through chemistry!
*Statistical citations:
https://psychopharmacologyinstitute.com
~RG