We have found that even subclinical levels of anxiety and depression can be important in terms of the experience of pain. Another factor that we spend a lot of time investigating in the pain research world is pain-related catastrophizing. It has a pervasive effect on people’s ability to manage pain. It is an emotional response to pain but it’s also a cognitive attentional response to pain, in which people become very focused on pain. They have a hard time distracting themselves and breaking their attention away. They also feel very helpless, as though there’s not much they can do to manage their pain. Another factor that I think most people are less aware of is the role of sleep disturbance. When we’ve looked at people who have chronic pain, we see that lots of people have clinically significant sleep disturbance. We also find, though, that even subclinical sleep disturbance--the typical American pattern of truncating sleep to 6, 6½, 7 hours increases people’s pain sensitivity. We think that this also impacts their ability to heal following surgery or an injury and we certainly see it contributing to people’s experience of pain and pain-related disabilities.