The inter-rater and test-retest reliabilities of prodromal symptoms in first-episode psychosis

Objective: As part of the DSM-IV field trial for psychotic disorders, the authors endeavoured to determine the reliability of the DSM-IV prodromal features for schizophrenia in a first-episode sample. Method: Fifty first-episode psychotic patients were assessed using a semistructured instrument to determine the presence/absence of nine prodromal symptoms, Inter-rater reliability data were calculated for 25 of the patients, and test-retest data were calculated for the remaining 25 patients. Results: Levels of reliability were poor. Conclusions: The results lend some support to American Psychiatric Association and World Health Organization decisions to omit specific criteria for prodromal features from their respective nosologies.