Association Between Peripheral Inflammatory and Hematological Markers and Suicide Attempts: A Retrospective Case-Control Study.

OBJECTIVE

This study aimed to compare peripheral inflammatory markers between patients presenting after a suicide attempt and healthy controls, and to examine differences between first-time and multiple attempters.

METHODS

This retrospective cross-sectional study included 90 patients presenting after a suicide attempt and 107 age- and sex-matched controls without psychiatric disorders between 2017 and 2024. Peripheral inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), basophil-to-lymphocyte ratio (BLR), and neutrophil-to-albumin ratio (NAR), were calculated from complete blood count parameters. C-reactive protein (CRP) data were available only for the patient group. Group comparisons used the independent samples t-test or Mann-Whitney U test, and correlations were assessed with Spearman's rho. Statistical significance was set at p<0.05.

RESULTS

Compared with controls, patients with suicide attempts had significantly higher white blood cell, neutrophil, and monocyte counts, as well as higher inflammatory indices (NLR, MLR, NAR; all p<0.01), and lower albumin, hemoglobin, and hematocrit levels (all p<0.01). BLR was significantly higher in individuals with multiple suicide attempts compared to first-time attempters (p=0.023) and showed a weak positive correlation with the number of attempts (r=0.246, p=0.019). CRP, NLR, MLR, and NAR were positively correlated with the number of psychiatric hospitalizations. No significant sex-based differences were observed in inflammatory indices.

CONCLUSION

Peripheral inflammatory markers were altered in patients presenting after a suicide attempt. BLR showed a modest association with multiple suicide attempts. These findings are preliminary and should be confirmed in prospective studies.