I have often wondered where this metaphor originated, or how it came to be. It is most apt. I find it most interesting how we carry along with us into present life the past. The 'set and setting' of the lived experience at the time of origin is so far removed from us today as to be unimaginable. Almost. I experience 'the black dog' more as a pensive sad, heavy hearted dog than a dog on my back. After all, the 'dog' is there in us already. To me, the dog is a companion in my gloom, not associated with a/the cause as such... Well done. Thanks