I came across this article and thought some of you might be interested. As you know, DH has struggled with severe back pain that very closely corresponds to his instability. Since all of the doctors he's ever seen, including the ones that he was when he was hospitalized for mental illness only prescribed pain killers and ordered scans, I found it exciting to see that some researchers are recognizing this connection.
Most people think that the mind and the body are separate and function independently. Instead, these two usually work together in shaping our experiences. Sometimes psychological factors can reduce or eliminate the effects of physical problems. For example, one line of research asked normal volunteers (that is, people who have never complained of chronic back pain) to undergo imaging procedures such as CT scans or MRI scans. Surprisingly, about 40% of these subjects had ruptured disks, pinched nerves, cracked vertebrae, or some other form of physical problem that should have produced significant back pain, but didn't. On the other end of the spectrum, there are some rare cases of conversion disorder: a psychiatric condition where the person feels chronic back pain, but there is no identifiable physical problem at all. In most cases, though, chronic back pain is a psychosomatic (literally, "mind-body") condition, where a real physical problem exists, but psychological factors play a large role in determining the person's experience of that problem. In some cases, mental processes such as dependence, depression, or frustration may make the pain worse; in other cases, a positive attitude and a sense of independence may lessen the pain.