Genealogy of Instruments for Prodrome Evaluation of Psychosis

Objective: Over the last 15 years, researchers from around the world have developed instruments for assessing the risk of conversion to psychosis. The objective of this article is to review the literature on these instruments by focusing on genealogy links and on their performance in predicting conversion to psychosis. Method: A systematic review of articles published since 1980 relating to risk assessment instruments for conversion to psychosis by manual search and consultation of electronic databases MEDLINE, EMBASE, and PsycINFO. Results: Three hundred ninety one (391) publications were selected and analyzed. Among these, 22 instruments were identified. These instruments are briefly described and placed on a timeline according to their year of publication. A code of positions, patterns, and forms is used to schematize the characteristics of each instrument. A table is presented to show changes in rates of conversion to psychosis within cohorts of subjects considered at risk according to the instruments. A second code of shades and outlines is used to schematize the characteristics of each cohort of patients. The two graphics set the stage for a discussion about the major strategies that were adopted to improve the performance of risk assessment instruments. Conclusion: These graphics allow a better understanding of the origin, evolution, current status, strengths, shortcomings, and future prospects of research on risk assessment instruments. Clinical Implications: The integration of theoretical approaches, the multicenter studies, and the pre-selection of patients with short questionnaires were the main strategies to improve the performance of instruments assessing the risk of conversion to psychosis. These instruments are better at predicting conversion to psychosis than conventional variables within a more limited time span and can therefore enable the evaluation of various risk factors and biomarkers that may be associated with psychosis. Limitations: The studies selected for this review of literature were not classified according to their methodological quality. These studies are based on heterogeneous populations and this must be taken into account when comparing the rates of conversion to psychosis. This review of literature was based on published data only and they were no direct communication with the authors of these instruments.