Systemic inflammatory biomarkers in Schizophrenia are changed by ECT administration and related to the treatment efficacy

Abstract

Immune inflammation has long been implicated in the pathogenesis of schizophrenia. Despite as a rapid and effective physical therapy, the role of immune inflammation in electroconvulsive therapy (ECT) for schizophrenia remains elusive. The neutrophils to lymphocytes (NLR), platelets to monocytes (PLR) and monocytes to lymphocytes (MLR) are inexpensive and accessible biomarkers of systemic inflammation. In this study, 70 schizophrenia patients and 70 age- and sex-matched healthy controls were recruited. The systemic inflammatory biomarkers were measured before and after ECT. Our results indicated schizophrenia had significantly higher peripheral NLR, PLR and MLR compared to health controls at baseline, while lymphocytes did not differ. After 6 ECT, the psychiatric symptoms were significantly improved, as demonstrated by the Positive and Negative Syndrome Scale (PANSS). However, there was a decline in cognitive function scores, as indicated by the Mini-Mental State Examination (MMSE). Notably, the neutrophils and NLR were significantly reduced following ECT. Although lymphocytes remained unchanged following ECT, responders had significantly higher lymphocytes compared to non-responders. Moreover, the linear regression analyses revealed that higher lymphocytes served as a predictor of larger improvement in positive symptom following ECT. Overall, our findings further highlighted the presence of systemic inflammation in schizophrenia patients, and that ECT may exert a therapeutic effect in part by attenuating systemic inflammation. Further research may therefore lead to new treatment strategies for schizophrenia targeting the immune system.

Keywords: Electroconvulsive therapy; Inflammation; Lymphocytes; NLR; Neutrophils; Schizophrenia.

Fig. 1

Differences in systemic inflammatory biomarkers in schizophrenia and controls and changes following ECT. Data was expressed as mean ± standard deviation (SD). a PLT was significantly elevated in schizophrenia compared to healthy controls (HCs) but remained stable following ECT. b Neutrophils was significantly elevated in schizophrenia and reduced following ECT. c Lymphocytes showed no differences between schizophrenia and HCs and kept stable following ECT. d Monocytes were significantly elevated in schizophrenia and decreased following ECT. e the neutrophil-to-lymphocyte ratio (NLR) was significantly higher in schizophrenia and reduced following ECT. f the PLT-to-lymphocyte ratio (PLR) was elevated in schizophrenia, while demonstrated no differences following ECT. g the monocytes- to-lymphocyte ratio (MLR) was higher in schizophrenia and significantly downregulated following ECT. *p < 0.05, **p < 0.01, ***p < 0.001, **** p < 0.0001