Are there different subsets of depression? How can we treat a condition which we know nothing about?

I think there are different subsets of what is called "depression". Some are caused by a person's subconscious or even conscious; some forms are due to diseases; and some forms are due to a combination of the two and genetics and a problem with the rewards, pleasure pathway in the brain. It's my belief that all currently FDA approved medications act only as placebos, accept maybe for a select few individuals that may have experienced a traumatic episode in their lives. I believe, for people that have been suffering from symptoms of depression, and chronic fatigue, and felt "off" all their life their is a genetic problem. Also, the drugs available to treat such "biological" depression (though I don't think it can be considered depression if it is biological or medical) is woefully impotent. We have the FDA not approving any drugs that actually are shown to relieve "depression"- especially in the 40-50% of of depressive patients that get no relief from the current "placebo" antidepressants-because they act to quickly and thus are deemed "addicting". The only thing the FDA will improve, and the pharmaceutical companies will pursue, are long acting drugs, that really have no effect except for the placebo effect. As someone that fits somewhere in these categories, I can attest I have never felt any benefit from every category of antidepressant when on it for weeks! Nothing. I can not believe that these drugs are even approved. The pharmaceutical companies, research bio-psychiatrists and all scientists involved in mental health have no concrete clue as to how the current so called antidepressants work (which I believe they don't), because they have not been able to measure quantified regions of the brain consistent with depression and subsequent improvement as related to these medications. Psychiatrists are a joke for people with a biological problem causing the depression or total body and brain loss of certain characteristics. The current research on antidepressants, is all by accident, coincidental. A certain drug designed for something else, happens to cause a lift in mood for a small subset of patients. Therefore it must be an antidepressant!....The serotonin theory pushed by some, has no basis at all, with regard to antidepressants. To prove this, they are several drugs approved to treat depression that actually reduce serotonin! Personally, I'd rather take the chances of living as a so called addicted person, with feelings, emotions, and contribution to society than suffer decades due to our government rulings and propaganda by psychiatrists and pharmaceutical companies.