Can we predict the onset of first-episode psychosis in a high-risk group?

Treating individuals in the prodromal phase preceding a first psychotic episode has long been a goal of clinicians, the aim being to prevent or minimize the harm inflicted by a psychosis. Before embarking on such a preventive approach, it is first necessary to characterize the features of impending psychosis. We have defined a set of criteria, based on various state and trait risk factors, to identify subjects likely to undergo transition to psychosis within a short time. We prospectively followed up 23 subjects fulfilling these criteria. Subjects were assessed monthly on measures of psychopathology for 12 months. Eleven of the 23 subjects (48%) made the transition to frank psychosis in the study period; the majority developed schizophrenia-like psychoses. Aberrant results on measures of psychopathology were found before the onset of psychosis. Our results indicate that it is possible to identify individuals who have a high likelihood of onset of psychosis within a brief follow-up period and that there are detectable mental state changes in this group prior to onset of psychosis. This finding lays the foundation for early treatment in an attempt to prevent, delay or minimize the severity of first psychotic episodes. (C) 1998 Rapid Science Ltd.