The notion of unitary psychosis: a conceptual history

Abstract

'Unitary psychosis' is the collective name for a set of disparate doctrines whose common denominator is the view that there is only one form of psychosis and that its diverse clinical presentations can be explained in terms of endogenous and exogenous factors. This paper examines the history of these doctrines since the eighteenth century in the work of their main sponsors and extricates their conceptual assumptions. It is shown that the nature of the debate between 'unitarians' and those who believed in the existence of separate diseases has changed throughout time, and that to these changes national differences have been important. Earlier discussions made use of conceptual and ontological argument; latter ones of clinical analysis; and the latest debate, that occurred during the 1970s, over-relied on statistical techniques and genetic analysis. The outcome of this long debate remains inconclusive.