Elevated neutrophil/lymphocyte ratio in patients with schizophrenia

Inflammatory mechanisms are reported to play important roles in the pathophysiology of schizophrenia. The neutrophil-lymphocyte ratio (NLR) is a simple and easily accessible indicator of the systemic inflammatory response. Our goal was to investigate whether NLR was higher in patients with schizophrenia than in healthy comparison subjects similar in age, sex, and body mass index. In this multicenter cross-sectional study, we analyzed 156 non-obese patients with schizophrenia and 89 healthy control subjects for complete blood count. The Brief Psychiatric Rating Scale was used to determine the severity of clinical pathology. The mean ± SD NLR of patients with schizophrenia was significantly higher than that of healthy controls (2.6 ± 1.1 vs. 1.9 ± 0.6, respectively, p < 0.001). NLR did not significantly correlate with severity and duration of schizophrenia (r = 0.065. p > 0.05). Our findings suggest that NLR levels are increased in physically healthy, non-obese, patients with schizophrenia when compared with physically and mentally healthy individuals. To our knowledge, this is the first study that demonstrated the association between NLR and schizophrenia.