Objective: Schizophrenia and other psychoses have devastating personal and social impacts and many efforts have been devoted to study ‎prodromal syndromes for psychosis in order to achieve earlier detection and interventions. However, only few studies have been ‎performed in developing countries on this subject, and there is a dearth of evidence in the Iranian population. In this study, we ‎focused on conversion rate to psychosis and changes in prodromal symptoms in a group of first-degree relatives of patients with ‎schizophrenia and to compare the conversion rate in those with and without prodromal symptoms as assessed by the Structured ‎Interview for Prodromal Syndromes (SIPS) and Scale of Prodromal Symptoms (SOPS).‎‎

Method: Participants were the first-degree relatives of hospitalized patients with schizophrenia at Roozbeh Hospital, Tehran, Iran. At baseline, ‎a trained psychiatrist interviewed the participants using the SIPS and the SOPS and assigned them to high- or low-risk groups either ‎based on the presence of prodromal criteria or seeking mental health services. After 12 months, the same examiner re-evaluated ‎the participants in order to determine the changes in their symptoms and identify the probable transitions to psychosis.‎

Results: One hundred participants, 50 participants within each of high- or low-risk groups, were recruited at baseline. Eight participants ‎dropped out of the study. At the follow-up, the rate of transition to full psychosis among high-risk group was 13% (95% CI [0.029, ‎‎0.23]), whereas none of the low-risk participants developed psychosis. None of the high-risk participants demonstrated attenuation ‎in their prodromal states after a one-year follow-up. In contrast, of the 50 low-risk participants, three experienced prodromal ‎symptoms for psychosis during this period. High-risk participant’s illustrated higher severity in almost all of the SOPS items compared ‎to the low-risk participants at both baseline and follow-up evaluations.‎

Conclusion: Prodromal syndrome for psychosis based on the SIPS and the SOPS was a predictive factor for transition to psychosis after a 12-‎month period in a group of first-degree relatives of patients with schizophrenia admitted to a psychiatric hospital in Iran. Conducting ‎further studies on this at-risk population is highly recommended in order to provide practical methods for early screening and ‎therapeutic interventions