Two interesting posts at Science and Reason:
1) This one reports on research linking hostility, anger, and depression to inflammation. Remember that inflamation is implicated in all sorts of chronic diseases: heart disease, cancer, rheumatism, etc.
2) This one reports on the link between stress and weight gain.
While researching for the book we read endless studies of the sort discussed in these posts. There really is a very impressive body of research now which links psychological traits and experiences with health-related physiological changes.
However, what we come back to time and again is our sense of disappointment with what we consider to be the overly simplistic psychology of this kind of research. When you come to look at them closely, constructs like 'stress' and 'hostility' just can't be made to do the work required of them. Let's return 'stress' to its natural home - helping us think about whether bridges and the like are liable to collapse.