Association of Neutrophil-to-Lymphocyte Ratio and Monocyte-to-Lymphocyte Ratio With Symptom Severity and Subjective Well-Being in Schizophrenia: A Cross-Sectional Study From Central India.

BACKGROUND: Systemic inflammation has increasingly been implicated in schizophrenia. The neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR), derived from routine complete blood count (CBC) investigations, are inexpensive inflammatory indices, but Indian data relating them to symptom severity and subjective well-being remain limited.

METHODS: This hospital-based cross-sectional study included 100 adults with schizophrenia (59 receiving antipsychotic treatment and 41 not currently receiving antipsychotic treatment, comprising newly diagnosed antipsychotic-naïve participants and previously diagnosed participants who had not received antipsychotic treatment for at least six months). CBC was performed in all enrolled participants according to the study investigation protocol. Symptom severity was assessed using the Brief Psychiatric Rating Scale (BPRS), and subjective well-being was assessed using the Subjective Well-being under Neuroleptic Treatment (SWN) scale. Parametric analyses were supplemented by nonparametric sensitivity analyses because NLR and MLR were nonnormally distributed. Treatment-stratified correlations and multivariable linear regression with robust standard errors were performed. An additional sensitivity analysis repeated the principal analyses after excluding the 18 newly diagnosed antipsychotic-naïve participants.

RESULTS: Patients receiving antipsychotic treatment had lower NLR (4.57 ± 1.90 vs. 8.94 ± 5.08) and MLR (0.50 ± 0.17 vs. 0.97 ± 0.50) than those not currently receiving treatment (both p < 0.001); however, the treatment-status groups also differed in illness duration and other baseline characteristics. In the pooled sample, NLR and MLR correlated positively with BPRS (r = 0.736 and 0.791; both p < 0.001). These associations remained significant within both treatment strata. Exploratory interaction analysis indicated that the MLR-BPRS association differed significantly by treatment status (interaction B = 30.40; 95% confidence interval (CI), 14.78-46.03; p < 0.001), whereas the NLR-by-treatment-status interaction was not significant. Pooled negative correlations with SWN did not persist within either treatment stratum. In adjusted models, NLR (B = 1.59; 95% CI, 0.76-2.42; p < 0.001) and MLR (B = 18.76; 95% CI, 11.15-26.37; p < 0.001) remained associated with BPRS after multivariable adjustment. After exclusion of the 18 newly diagnosed antipsychotic-naïve participants (n = 82), between-group differences in NLR and MLR and their associations with BPRS persisted; the MLR-by-treatment-status interaction remained significant but was attenuated (B = 24.82; 95% CI, 5.50-44.15; p = 0.012).

CONCLUSION: Higher NLR and MLR were associated with greater schizophrenia symptom severity within treatment strata and after multivariable adjustment. Between-group differences according to antipsychotic treatment status should be interpreted cautiously because treatment exposure was observational and the groups differed in baseline clinical characteristics.