Abstract
This chapter discusses the psychosocial influences on immunity and infectious disease in humans. There is evidence for the plausibility of psychosocial influences on infectious disease in humans as well as evidence for a role of stress in determining susceptibility for a small number of infectious agents. Little is known about the characteristics of psychosocial factors that increase or decrease risk of disease onset and progression and of the nature of behavioral, endocrine, and immune changes that are responsible for psychosocial-induced changes in disease risk. Until there is more empirical evidence for specific mechanisms linking psychosocial factors to infectious disease, there would be little real understanding of the extent to which evidence deriving from present work generalizes to other disease models. It is likely that the following years would result in an understanding of the relations between psychosocial factors and immunity, the mechanisms that link psychosocial influence to immune change, and the range of immune function that is subject to alteration.