Psychoneuroimmunology

Psychoneuroimmunology is an interdisciplinary field that involves the investigation of the bidirectional relationships between the mind, brain, and immune system and the implications of these relationships for clinical disease. This field is highly relevant to health psychology for a number of reasons. First, studies in this field examine the physiological linkages that explain relationships between psychological factors and the etiology and progression of disease. The immune system is a major pathophysiological system whose dysfunctions can play a critical role in the etiology and progression of a variety of diseases, including infections, the autoimmune diseases (such as rheumatoid arthritis), some forms of cancer, and even cardiovascular disease. By understanding how psychological factors and their neurophysiological correlates affect the immune system, it is possible to flesh out part of the mechanistic pathway that links psychological factors to disease. Specifying a mechanistic or mediational pathway is central to establishing a causal relationship between a specific psychological factor and a health outcome (see Figure 5.1 for an X-Y-Z schematic representation of central components of this pathway; Kemeny, 2003). Psychoneuroimmunology studies can provide evidence for each of the links in this pathway and can point to critical psychological elicitors and mediating systems.