Association between Changes in Total Antioxidant Levels and Clinical Symptom Improvement in Patients with Antipsychotic-Naïve First-Episode Schizophrenia after 3 Months of Risperidone Monotherapy

Schizophrenia (SCZ) is associated with aberrant redox regulation in the early stages of brain development. There is growing evidence that the antioxidant defense system is closely associated with the therapeutic response to antipsychotics in SCZ patients. The aim of this study was to examine the effect of risperidone monotherapy on total antioxidant status (TAS) and the relationship between symptom improvement and changes in TAS in patients with antipsychotic-naïve first-episode (ANFE) SCZ. Clinical symptoms were evaluated using the Positive and Negative Syndrome Scale (PANSS). Two hundred and forty-six ANFE patients were treated with risperidone for 3 months. PANSS and TAS levels were assessed at baseline and at a 3-month follow-up. Relative to healthy controls, ANFE patients had higher TAS levels, which increased even further during the treatment. Moreover, baseline TAS levels were a predictor of symptom reduction after risperidone treatment. In addition, there was a significant association between increased TAS levels and the decreased cognitive factor. Our findings suggest that antioxidant protection is possibly associated with clinical improvement in ANFE patients after risperidone treatment.