A critical review of the biopsychosocial model N. McLaren Objective: The aim of this review is to provide an analysis of the epistemic status of the biopsychosocial model. Method: A critical comparison of the biopsychosocial model with the general concept of models. Results: In its present form, the biopsychosocial model is so seriously flawed that its continued use in psychiatry is not justified. Conclusion: Further development of theory-based models in psychiatry is urgently needed. Key words: biopsychosocial model, models in psychiatry. Australian and New Zealand Journal of Psychiatry 1998; 32:86-92 In a series of papers starting in 1960, Engel [1-5] outlined what he saw as deficiencies in the dominant 'biomedical model' as it applied to medicine in general and to psychiatry in particular. He charac- te1ised the biomedical model as reductionist (' ... the language of chemistry and physics will ultimately suffice to explain biological phenomena' [2, p.130]) and dualist (i.e. it separated the intangible mind from the physical body). Despite the undoubted success of the biomedical model, Engel saw this tendency to discount mental life as a major weakness. Humans are not just biological preparations, he argued, but exist as sentient beings in a causally significant psy- chological and sociological milieu for which the bio- medical model can give no account. A true science of human affairs, he averred, would be able to incorpo- rate this milieu. Engel acknowledged that his complaints against the dominant ethos were not new, that 'psychosomat- ic medicine' had been offered as the bridge between the 'two parallel but independent ideologies of med- icine, the biological and the psychosocial'. That par- ticular bridge had failed, he believed, because it was forced to conform to 'scientific methodologies basi- N. McLaren, Psychiatrist in Private Practice PO Box 282, Sanderson, Northern Territory 0812, Australia Received 26 March 1997; revised 18 June 1997; accepted 23 June 1997. q cally mechanistic and reductionist in conception and inappropriate for many of the problems under study' [2, p.134]. This, he suggested, was the fault of the dominant model of science: a rigid, reductionist pos- itivism that could not take account of human factors and, therefore, ignored them. Engel argued that, intangible or not, human factors are not irrelevant but apply just as strongly in orthodox illnesses, such as diabetes, as in classic mental disorders, such as schiz- ophrenia. In his view, the 'psychosomatic' model had failed in that it had been based on Freudian and Meyerian concepts, and he implicitly acknowledged that there was no way these could be formalised into a system compatible with the biomedical model. In the first place, constructs based in these theories were not amenable to analysis using the methodology of modern science and second, empirical research failed to validate crucial elements such as the disease- specificity model. Therefore, in order to advance where psychosomatic medicine had become mired in irrelevancies, he suggested a new approach: the biopsychosocial model. This, he insisted, was a sci- entific model where the psychosomatic had not been. In place of the unproductive psychoanalytic model, he suggested that a new approach, Von Bertalanffy's General Systems Theory (GST) [6], provided a suit- able orientation. Its particular strength lay in its pur- ported capacity to permit scientific investigation