The Role of Developmental Factors in Susceptibility to Disease

An attempt is made to provide a perspective within which to view the role of developmental processes in the pathogenesis of disease. Given the presence of potentially pathogenic stimuli, conditions would be optimal for the development of manifest disease if there exists a biologic “vulnerability,” changes in the psychosocial environment are perceived as “stressful,” and the individual is unable to cope with the altered environmental demands. Experiences that occur during early life represent only one of the factors that could contribute to the manner in which the individual perceives and adapts to changes within his environment. Examples from the animal research literature illustrate the potential of events occurring during the course of development to alter specific sensory capacities in the adult exposed to extraordinary environmental demands, and to modify psychophysiological function and ultimate disease susceptibility. Experientially determined differences in disease susceptibility, however, depend upon the nature of the disease process under study. In the case of experimentally-induced gastric lesions, early life experiences interact with subsequent social factors to decrease susceptibility even in animals genetically predisposed to the development of such lesions. It is suggested that events occurring during the course of development result in chronic changes which contribute to the psychophysiological background upon which potentially pathogenic stimulation is superimposed.