From simplicity to complexity (1950-1990): the case of peptic ulceration--I. Human studies

The problem of the psychobiology of human peptic ulceration has become very much more complicated in the past 20 years, once it was realized that it was not one disease but many. It is recognized that 29 different forms exist. Two common but distinct forms of the disease are characterized by elevated or normal levels of pepsinogen-I. In a third form elevated levels of pepsinogen-II occur; however, this particular increase imparts more of a risk by a factor of 3 for gastric than for duodenal ulcer. In the light of such facts, all studies on the psychological characteristics and social contexts that characterize the onset of the disease must be reevaluated. In addition, a number of different pathophysiological disturbances of the regulation of gastric acid secretion, motility, and bicarbonate secretion characterize patients with the disease, and further subdivide patients with increased or normal pepsinogen-I levels.