More pain = more pain
The endlessly quotable Lorimer Moseley summarizes the role of the mind in chronic pain for TheConversation.com:
This is where our understanding of pain itself becomes part of a vicious cycle. We know that as pain persists the nociception [danger signalling] system becomes more sensitive. [Indeed we do. See Woolf.] What this means is that the spinal cord sends danger messages to the brain at a rate that overestimates the true danger level. This is a normal adaption to persistent firing of spinal nociceptors. Because pain is (wrongly) interpreted to be a measure of tissue damage, the brain has no option but to presume that the tissues are becoming more damaged. So when pain persists, we automatically assume that tissue damage persists.
I think it goes like this: “more pain = more damage = more danger = more pain” and so on and so forth.
And so, “Pain really is in the mind, but not in the way you think” — a good phrase. Partly inspired by this, I’ve written a new section for my low back pain book, which means that Dr. Moseley’s very valuable perspective is now quite well represented there.