Clinical symptom improvement following modified electroconvulsive therapy is associated with modulation of peripheral inflammatory markers in schizophrenia

BACKGROUND Schizophrenia is a severe neuropsychiatric disorder with unclear pathogenesis, although immune-inflammatory pathways are being increasingly implicated. Elevated proinflammatory cytokines are consistently observed in patients with schizophrenia, suggesting a state of chronic low-grade inflammation. Modified electroconvulsive therapy (MECT) is an effective biological intervention for treatment-resistant schizophrenia, but its mechanisms remain incompletely understood. AIM To examine the association between MECT-induced changes in immunoinflammatory markers and clinical improvement in schizophrenia. METHODS In this prospective study, 619 patients with schizophrenia underwent MECT. Peripheral immunoinflammatory markers, including monocyte-to-lymphocyte ratio (MLR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, and systemic immune-inflammatory index (SII), were measured before and after treatment. Clinical symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS). Correlation and logistic regression analyses were applied to evaluate associations, and receiver operating characteristic analysis was used to assess predictive performance. RESULTS After MECT, significant reductions were observed in PANSS scores and most peripheral inflammatory markers (MLR, NLR and SII; all P < 0.05). The decreases in MLR, NLR, and SII showed a significant positive correlation with the PANSS score reduction rate (P < 0.05). Patients with marked clinical improvement showed greater decreases in inflammatory markers. Logistic regression identifies the change in MLR before and after treatment (ΔMLR) as a strong predictor of treatment response, with each 0.1-unit increase associated with a 57% greater probability of clinical symptom improvement (odds ratios = 1.57, P < 0.001). Receiver operating characteristic analysis demonstrated that ΔMLR had significant predictive value for MECT efficacy (area under the curve = 0.731, P < 0.001), with an optimal cutoff value of 0.075. CONCLUSION MECT modulates peripheral immune inflammation in schizophrenia, and these changes correlate with clinical improvement. ΔMLR may serve as a valuable predictor of MECT treatment response.