Dorien Nieman1, Stephan Ruhrmann2, Mirjam van Tricht1, Hans Koelman1, Lieuwe de Haan1; 1University of Amsterdam, 2University of Cologne
Accumulating evidence suggests that a blend of clinical staging and profiling, which naturally incorporates an clinical high-risk phase, might be a better guide for treatment of patients in different stages of psychiatric illness than the categorical DSM diagnostic system. The prognostic index (PI) is a well-established and widespread risk-modelling procedure that is used for multivariate clinical staging and profiling in somatic medicine. In a PI, individual prognostic scores are stratified into different risk classes for clinical usability. We investigated a PI in subjects at clinical high-risk for a first psychotic episode. Out of a comprehensive set of predictors, the P300 event related potential and premorbid adjustment were identified as the key elements in an individualized prognostic score. The individual prognostic scores were further stratified into three risk classes. In the class with the worst premorbid adjustment and P300 deficits, 74% of the subjects made a transition to a first psychosis whereas in the lowest risk class only 4% transitioned. Thus, compared with the overall transition rate of 29% predicted by the inclusion criteria, application of the PI improved individual risk estimation significantly. Research should focus on benign treatments to reduce P300 deficits in the early stages. Perhaps objective biomarkers such as the P300 combined with clinical symptoms, existential concerns and psychosocial functioning could be used in the future in a clinical staging model to assess a patients’ individual risk and need for particular types of care instead of the current general characterisation of the patients’ symptoms with respect to the broad DSM criteria.
