With the bulk of prescription drugs, the generic version can vary slightly from how the brand name behaves without any ill effects to the patient. But there are some drugs that have what is called a "narrow therapeutic index." This means that even a small variation in the way the drug behaves in the bloodstream can have ill effects. Bupropion may fall into this category.

Unfortunately, in many cases patients don't actually have any choice in whether the drug they're taking is generic or brand name. Insurance companies hate to pay for brand name medications. If a generic version exists, that's what they want the patient to take, and they will almost always refuse to pay for a brand name drug in that situation. Even if the doctor writes "Brand Name Medically Necessary" on the prescription slip, chances are there's still going to be a battle with the insurance company.

If you have switched from a brand name antidepressant that was working for you to a generic antidepressant that doesn't seem to be working as well, it's probably a good idea to keep a record not only of your moods, but also of any possible side effects. This will bolster your case when you and your doctor make your push to have your insurance company pay for the brand name.