Prodromal symptoms of relapse in schizophrenia: a review

It is often stated that there are identifiable prodromal symptoms of psychosis in patients suffering from schizophrenia. In this article, we review the evidence for the existence of such prodromal symptoms. Computerized and direct searches of the psychiatric literature were conducted to identify relevant reports. The methods and findings of the studies were then examined for their relevance to several issues concerning prodromal symptoms. We found that very few studies have directly assessed the relationship between putative prodromal symptoms and the exacerbation of psychosis. The research that has been reported suggests that prodromal symptoms have only modest power as predictors of relapse. It appears that while some individual schizophrenia patients may show reasonably consistent patterns of prodromal symptoms, such symptoms are probably of limited general value in predicting psychosis. Two particular issues that warrant further investigation are individual differences in patterns of prodromal symptoms and the extent to which such symptoms actually precede changes in level of psychosis.