Neutrophil-to-lymphocyte ratio exhibits the different correlation with psychiatric symptoms in the different status of antipsychotic therapy in schizophrenia: a large-scale retrospective cross-sectional study.

Abstract

Background There are some conflicting results regarding the neutrophil-to-lymphocyte ratio (NLR) and the severity of disease in patients with schizophrenia. Inconsistent findings among the studies might be caused by several limitations, such as, heterogeneous patient populations lacking stratification by antipsychotic therapy, small sample sizes lacking statistical power, ignoring multicollinearity between NLR and other related factors, and lack of controlling for potential confounding factors. In this study, we evaluated the possible correlation between NLR and disease severity as manifested in clinical scores in patients with schizophrenia. In particular, NLR is correlated with discrepant psychiatric symptoms in the different status of antipsychotic medication administration. Methods This was a cross-sectional study conducted in our hospital. We identified inpatients with schizophrenia between July 12, 2018 and March 27, 2019 and who had NLR, Clinical Global Impression Severity scale (CGIS) and Brief Psychiatric Rating Scale (BPRS) scores. Results The records of 1144 identified patients (32.4% male, 76.6% with NLR ≤ 1.98, and 10.8% drug-free patients) were analyzed. Multivariate logistic regression showed that NLR was positively associated with worse psychiatric symptoms, both the CGIS score (moderately ill: OR: 63.578, p = 0.011; severely ill: OR: 53.617, p = 0.015) and the BPRS total score (moderately ill: OR: 4.049, p = 0.055; severely ill: OR: 4.312, p = 0.045). In the drug-therapy subgroup, there was a negative correlation between NLR and severe negative symptoms (severely ill: OR: 0.850, p = 0.018) after controlling for potential confounding factors. Conclusions The study is the first to confirm the hypothesis that NLR is independently associated with severe psychopathology in schizophrenia. There is the different correlation between NLR and psychiatric symptoms in the different status of antipsychotic therapy. Therefore, NLR is not appropriate to be an inflammatory biomarker for assessment of disease severity, but provide potential mechanistic insights on specific pathological cellular processes, as well be a potential target to improve the course of the psychotic disorder.