Evaluation of the correlation between peripheral inflammatory markers and suicide risk in drug-naive first-episode schizophrenia

Abstract

Introduction: Patients with schizophrenia have a higher lifetime prevalence of suicidal behavior (SB) compared to the general population. Therefore, understanding the possible neurobiology of suicide and predicting the risk of suicide in schizophrenia is a solemnly critical issue. Methods: 31 drug-naïve first episode schizophrenia (FES) patients with current SB (FES-S), 69 drug-naive patients with first episode schizophrenia without SB (FES-NS), and 69 drug-naïve non-psychotic patients with current SB (NPS) who were diagnosed according to The Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) participated the study. The control group (HC) consisted of 127 individuals matched with the patients. Symptoms at the time of evaluation were assessed using The Positive and Negative Syndrome Scale (PANSS) and Columbia Suicide Severity Rating Scale (CSSRS). Blood samples were collected from all participants to determine White blood cell (WBC), neutrophil, monocyte, albumin, C-reactive protein (CRP), Lymphocyte, and Platelet levels and to measure this protein ratio. Results: The blood levels of WBC, neutrophil, monocyte, albumin, CRP, and Neutrophil/Albumin Ratio (NAR) were higher in all patient groups compared to HC. CRP/Albumin Ratio (CAR) value was observed to be highest in the NPS group. Monocyte/Lymphocyte Ratio (MLR) value was significantly higher in patients with FES compared to HC. There were no significant differences between the FES-S group and the FES-NS and NPS groups. Conclusion: It can be suggested that although inflammation is not a predictor for suicide attempts in schizophrenia, it is associated with the degree of suicide risk in schizophrenia. In addition, the strong relationship between suicide and psychiatric disorders can be the main reason for high peripheral inflammation levels in suicidal patients.