" There is the subconscious, automatic negative feelings of Depression but there is always a reaction that fuels the downward spiral." Depression that you are describing is the one that comes from the mind or subjective perception, right?
I agree with everything you said 100% and antidepressants should never be used in this case.
I meant that sometimes Depression or feeling of despair and darkness can be brought on by purely PHYSIOLOGICAL changes. That's when the use of psych meds is justified and is often necessary. You have to be a very experienced meditator to rationilize with that kind of emotional pain. It's comparable to physical pain if you broke your leg: you can try to separate yorself from that pain using the power of your mind or you can go to the hospital and get it treated with medication.