Association between Suicidal Ideation and Immune Parameters in First-episode Patients with Schizophrenia

Disturbed immunity and inflammation have been associated with the pathogenesis of schizophrenia (SZ) and suicidal behaviors. We hypothesized that the neutrophil-tolymphocyte ratio (NLR) was associated with the increased risk of suicide ideation (SI) in patients with SZ.

A total of 97 drug-naïve first-episode patients with SZ (15 with SI and 82 without SI) were recruited in the present study. The symptom severity was assessed using the Positive and Negative Syndrome Scale (PANSS), and differential white cell counts and SI were assessed for all patients.

Patients in the SI group had higher NLR values and more severe clinical symptoms than the non-SI group (all p<0.05). Differences remained significant when controlling for smoking, sex, BMI, and age. Logistic regression analysis showed that NLR was an independent predictor of SI in firstepisode patients with SZ after controlling for clinical symptoms, smoking status, marital status, education, sex, body mass index (BMI), and age.

This study indicates a predictive role of NLR in SI at the first onset of SZ. It also suggests that monitoring NLR could be a useful clinical tool for identifying patients who may be at higher risk for SI, particularly at the onset of the disorder.

Our findings add to the understanding of the biological factors that may contribute to SI in SZ.