IS THE BIOPSYCHOSOCIAL MODEL STILL A USEF UL CONSTRUCT

In 1977, G. L. Engel proposed a biopsychosocial model, applicable to a ll illness and disease. It was based on systems theory which orders th e world into a ladder (of systems) from the most elementary particles to social phenomena and the cosmos. Systems theory was proposed to com bat reductionism and to deal with complexity and order. Central to tha t theory is the concept of emergence that the properties of each ''hig her'' or more complex system are not explainable either by their compo nents nor by those at a lower level. However, no one form of complexit y exists. Some forms of complexity arise out of the interactions of th e components, especially as the result of feed-back, which in turn all ows us to understand order, and sudden change. Living systems are char acterized by genetic programs, self-replication, self-organization and adaptability. These properties exist at every ''level'', and thus mak e systems theory and its hierarchies no longer necessary, and also eli minate the concept of emergence.