Adapting the Early Recognition Inventory ERIraos to Estonian: A Validation Study.

Aim: Validated assessment tools are needed to identify clinically high risk for psychosis. This study aimed to validate the early recognition inventory ERIraos, which consists of the ERIraos Checklist for risk screening and the ERIraos Symptom List for a more thorough risk assessment in the Estonian language to detect psychotic prodromal symptoms. Methods: A prospective cohort study provided an opportunity to evaluate the characteristics of the ERIraos instrument in predicting the increased risk of a psychotic disorder in the future. The 177 study participants, aged 13-42 years old, were divided into groups without an increased risk and three risk groups with different risk severity levels based on the ERIraos Symptom List assessment. Results: The results indicated excellent inter-rater reliability for the ERIraos Symptom List total score. The ability of the ERIraos checklist to screen persons with an elevated psychosis risk was very good (ROC-AUC = 0.86). The capability of the ERIraos Symptom List scores to predict the probability of transitioning to psychosis within 2 years was very good (ROC-AUC = 0.83). Brief limited intermittent psychotic symptoms and observable behavioural and affective symptoms were statistically significant predictors of transition to psychosis. There were strong and statistically significant correlations between the ERIraos Symptom List scores and other clinical measures assessing functioning and psychopathology. Conclusions: The results of this study demonstrate the reliability and validity of the Estonian version of the ERIraos instrument and support the usability of ERIraos as a two-step tool for the early recognition of psychosis risk.