Predicting the development of schizophrenia in high-risk populations: systematic review of the predictive validity of prodromal criteria

Background There is a great deal of debate on the usefulness and accuracy of prodromal criteria in predicting schizophrenia. The risk of treating people who screen false positive with medication is considerable. Yet intervening during the prodromal stage of illness may reduce the burden caused by schizophrenia. Aims To draw together the evidence base for the predictive validity of prodromal criteria in identifying individuals at high risk of developing schizophrenia. Method We conducted a systematic review of prospective studies investigating the predictive validity of prodromal criteria in schizophrenia. Results Our study found two main criteria, ultra-high-risk criteria and basic-symptoms criteria, used in studies investigating the predictive validity of prodromal symptoms. The sensitivity and specificity of ultra-high-risk criteria was 0.81 (95% Cl 0.76-0.85) and 0.67 (95% Cl 0.64-0.70) respectively and for basic-symptoms criteria sensitivity and specificity was 0.97 (95% CI 0.91-1.00) and 0.59 (95% CI 0.48-0.70) respectively. Conclusions Both ultra-high-risk criteria and basic-symptoms criteria are useful in predicting the development of schizophrenia among high-risk populations.