Concordance is based on the idea that patients and practitioners should work together towards an agreement on treatment choice. This requires a redefinition of the relations and encounters between doctors and their patients. This redefinition emphasizes the need for patient involvement and participation. In this article we examine concordance against the background of wider social change, structural as well as interpersonal. We focus in particular on challenges to trust, noting that the almost instinctive trust that people formerly had for professional experts has for many reasons diminished. One consequence of this, we suggest, is that concordance is being espoused at a time when its accomplishment may be particularly threatened. In fact there are strong grounds for claiming that support for the notion of concordance could possibly result in a growth of 'hidden' communication pathologies by means of what the social theorist Habermas (1984) has termed 'systematically distorted communication'.