"not sure where you are from, but here in the US pharmaceutical companies are allowed to market to the public, which is why people are always pushing them. There hasn't ever been a study that actually proved a depressed brain to be chemically out of balance."

I would like to point out, in response to this, that the experience of physical pain is not attributable to an endogenous opiate deficiency either. However, pain is treatable with opiates.

It is entirely possible to elaborate on a naturally occuring system in the body to acheive therapeutic benefit.