The role of plasma oxytocin in early-onset schizophrenia: implications for disease severity and early intervention

INTRODUCTION: Early-onset schizophrenia (EOS) is a severe psychiatric disorder with poor long-term outcomes. It offers a unique opportunity to examine the neurobiological mechanisms of schizophrenia without the confounding effects of adult environmental factors. Oxytocin (OXT), a neuropeptide involved in social and emotional regulation, has been linked to several psychiatric conditions, including schizophrenia. This study investigated associations between plasma OXT levels, disease severity, personality traits, and childhood trauma in EOS. METHODS: Participants were 118 patients with EOS and 76 healthy controls (HC). Plasma OXT levels were measured, symptom severity was assessed using the Positive and Negative Syndrome Scale (PANSS), personality traits were evaluated with the Chinese Adolescent Personality Five-Factor Inventory, and childhood trauma was measured using the Childhood Trauma Questionnaire-Short Form. Analyses included independent-samples t tests, chi-square tests, binary logistic regression, receiver operating characteristic (ROC) curve analysis, and correlation analysis using SPSS and R. RESULTS: EOS patients had significantly lower plasma OXT levels than HC (P < 0.001). Sex, extraversion, OXT levels, and emotional abuse predicted EOS, explaining 55.4% of the variance. OXT levels showed moderate diagnostic utility (Area under the curve, AUC = 0.776) with an optimal cutoff of 183.428 pg/mL. In patients with milder symptoms (PANSS < 65), OXT levels positively correlated with symptom severity (r = 0.482, P = 0.020); no correlation was found in severe cases. CONCLUSIONS: Altered OXT levels may be associated with EOS pathophysiology, particularly in early stages. Plasma OXT levels may have potential as biomarkers for early diagnosis and intervention, pending validation in longitudinal studies, supporting future research on personalized treatment strategies.