I can understand the idea of reasoning with depression well. I feel the same way. I've had psilocybin mushrooms help me launch  myself out of depressions by giving me access to other modes of thinking, thereby seeing the things that were oppressive as something different and breaking the cycle. In my case the depressions were a result of faulty thinking which lead to chemical imbalance. Psychedelics helped change both, while maybe your typical pharmaceuticals mainly address the chemical aspect? It's really hard to say because these things are so intertwined... 

What smoking device do you use? I've never felt spice to be taxing on the lungs. I feel nothing at all - using a GVG. I've only tried changa once and was a bit confused as to how to dose it correctly. But you might also be interested in dosing harmalas orally prior to a dmt session. It intensifies and prolongs the experience as well.

I have not tried bufo and know next to nothing about it. I suppose some day I will look into it, but for now I am content with spice and mushrooms.

cheers & love

Enoon