Wellbutrin/ bupropion, would it not work if...?

The cause of depression is multi-factorial, not solely based on the lack of dopamine. Up-regulation of dopamine receptors is a theory behind depression, with bupropion acting to down-regulate the receptors. This down-regulation takes at least 6-8 weeks, the time at which clinical improvement usually begins (but response varies). I just want to comment that suddenly stopping the drug will induce withdrawal symptoms (NOTHING to do with withdrawal related to addiction). Just to comment on the answer from above, anti-depressants have been well studied in controlling depression (and promoting remission), whereas "natural remedies", for the most part, have not been. Considering the majority of medications are derived from plants, natural remedies should be considered drugs as well - if properly studied (such as St John's Wort), you would see that their side effects are just as many as conventional drugs.