On the surface, the addition f clinical psychologists to the health care team may appear to be an unproblematic process. A need for psychological expertise among medical patients has been identified, and psychologists have the requisite expertise. We hope to show in this article, however, that the involvement f the psychologist in the health team is a complex matter, subject to a number f difficulties, not the least f which is the question f professional power relationships. A prior issue, however, is that f the place f clinical psychology with regard to medical theory and practice. This interdisciplinary interface occurs within a "generalprofessional culture which cuts across regional boundaries and which is limited more by class and by educational background than by national origin" (Swartz, 1985, p. 727). Interprofessional relationships within various Western contexts are therefore discussed without particular reference to nationality.
Toulmin (1978) pointed out that there are numerous medical models or ways f conceptualizing disease and illness, and these models take account f psychosocial issues to varying degrees. A distinction that may be useful in discussing these issues in medicine is that commonly drawn by medical anthropologists between disease and illness. Disease may be understood as the biological component f sickness, whereas illness has been defined as a subjective experience consisting f "an array f discomforts and psychosocial dislocations resulting from interaction f a person with the environment" (Barondess, 1979, p. 375). Disease is neither a necessary nor a sufficient condition for the presence f illness (Sullivan, 1986), in that it is possible to experience the social role f illness without any biological pathology. Conversely, pathology may exist, without any subjective experience f it, and hence a person may have a disease without being ill.
Biomedicine is the dominant model in Western medicine (Fabrega, 1978). The biomedical model is said to explain health and sickness in terms f the physical, chemical, and physiological changes in the bodily systems f an individual, divorced from the person's experience f sickness and from the social context (Kleinman, 1978). The model's strength lies in its elucidation f the biological mechanisms f sickness, but it is limited by its neglect f psychosocial aspects (Bignami, 1982; Engel, 1977; Fabrega, 1978; Kleinman, 1978; McHugh & Vallis, 1986a; Rogers, 1982). Tancredi and Edlund (1983) commented that this model does not recognize "the fact that medicine is as much a social science as it is a biological science" (p. 314). Toulmin (1978) suggested that the biomedical model inappropriately facilitates the patient's being seen as the sum total f his or her biological ailments. In other words, biomedicine focuses on disease to the exclusion f illness.
As an alternative to the biomedical model, Engel (1977) developed the biopsychosocial model, which is a systems