The power of the imagination is a great factor in medicine.
It may produce diseases in man and in animals, and it may cure them.
– Paracelsus, sixteenth century
By no means should the above observation be equated with a contemporary de“nition of health psychology, but in his quote, the noted reformer and physician Paracelsus argues that disease, neither in its etiology nor in its cure, can be totally understood in terms limited to the realm of the soma. This is the essence of the “eld of health psychology that disease processes cannot be understood solely in terms of biological and physiological parameters. Instead, a biopsy-chosocial model better represents a more complete picture of disease, illness, health, and wellness.
Rather than underscoring the primacy of somatic variables, such a model (see Schwartz, 1982) contends that biological, psychological, and social factors all constitute important and crucial indices of a de“nition of disease with regard to issues of etiology, pathogenesis, course, and treatment. Recent research suggests that less than 25% of physical complaints presented to primary care physicians have known or demonstrable organic or biological etiologies, greatly highlighting the need for a more complete model (Nezu, Nezu, & Lombardo, 2001).
Such a view is consistent with a planned critical multiplism perspective (Shadish, 1986), which is a methodological approach whereby attempts are made to minimize the biases inherent in any univariate search for knowledge. During the past two decades, efforts by a wide range of psychologists interested in disease and illness have provided varying types of support for this biopsychosocial model using this multivariate perspective.
Starting with simpler questions, sueh as what types of psychological processes affect illness, the “eld of health psychology has since expanded greatly in terms of its scope, depth, and impact. For example, Taylor»s (1990) con“dent prediction that succinct papers reviewing the current status of health psychology would disappear due to the «diversity of issues studied and the complexity and sophistication of the models and designs used to explore them appears to have been con“rmed. Initially, the “eld was composed of researchers and practitioners with common interests in issues related to health and illness who were trained in more traditional (hut varied) areas of psychology.
The diversity of conceptual approaches, models, and designs brought together by these individuals have helped to establish a “eld that is broad in scope, eclectic, multidisciplinary, dynamic, and allowing for creative developments. Training programs in health psychology have tapped this breadth and students now have signi“cant exposure to neurology, endocrinology, immunology, public health, epidemiology, and other medical subspecialties, in addition to a solid grounding in psychology (Brannon & Feist, 1992).