Association between the Korea-Polyenvironmental Risk Score and Clinical Outcomes in Schizophrenia Spectrum Disorders

Background: Evidence suggests that environmental factors increase the risk of psychosis development and influence the prognosis of psychotic disorders. This study examined the discriminative validity of the Korea-Polyenvironmental Risk Score (K-PERS) in differentiating patients with schizophrenia spectrum disorders (SSDs) from healthy controls (HCs). In addition, we evaluated its associations with baseline clinical characteristics and short-term clinical outcomes. Study Design: Data were obtained from participants of the Korea Early Psychosis Study, who were assessed using K-PERS and underwent clinical evaluations at baseline and at 2, 6, and 12 months. Matched HCs were recruited for comparison. Psychopathology, cognitive functioning, and socio-occupational functioning were assessed using the Positive and Negative Syndrome Scale (PANSS), Prospective and Retrospective Memory Questionnaire (PRMQ), and Social and Occupational Functioning Assessment Scale (SOFAS). Treatment response, remission, and recovery were evaluated based on predefined criteria. Results: A total of 224 subjects with SSD and 203 HC were enrolled in this study. K-PERS-I and K-PERS-II demonstrated good predictive performance, with area under the curve values of 0.738 and 0.754, respectively. At baseline, K-PERS-I and K-PERS-II were significantly associated with depressive and negative symptoms, PRMQ scores, SOFAS scores, and various self-reported measures. Importantly, several individual item scores or total score of K-PERS predicted treatment response, remission, or recovery. Conclusions: K-PERS has a good discriminative ability for identifying SSDs within the general population. Furthermore, K-PERS is associated with symptom severity, cognitive performance, and socio-occupational functioning, and it significantly influences the illness course.