What a lot of medical professionals don't point out is, that there are different types of depression. It can be chemical, physical, or psychological. I would first get a really good physical, with a complete blood workup. Your vitamin stores could be low, you could have a mild hormonal imbalance. It is not always environmental. It is just always presumed by society and doctors for some unknown, stupid reasonings. Assume it is environmental lastly. Get yourself completely checked out physically first, my friend. PS: Are you on any other meds that you take regularly? That could also possibly play a role. Go the full gamut of investigation. And get a second, even third opinion. Listen to your body, its talking to you. :)