On the notion of psychosis: the DSM-IV in perspective.

Using a historical overview and a conceptual analysis of the notion of psychosis, the DSM-IV suggestion to narrow down the notion of psychosis to delusions and hallucinations is examined. It is argued that the suggestion continues a trend in modern psychiatry, and that, perhaps more than others, it might lead to the (mis)identification of the notion of psychosis with the notion of error, which fails to demarcate disordered reality representation--as in delusions and hallucinations--from normal reality representation. Finally, the notion of (impaired) reality testing is presented as permitting such a demarcation, and it is concluded that it is therefore clinically useful and should be preserved, at least for the time being, in the notion of psychosis, including the narrow sense of the notion of psychosis as suggested in the DSM-IV.