Journal of International Psychiatry

Objective: The aim of this study was to assess the correlation between systemic immune-inflammatory index (SII) and suicidal ideation in children and adolescents with depression (MDD). Methods: This retrospective study included 795 children and adolescents with MDD who were hospitalized in third people’s hospitals of Fuyang. Patients were grouped according to the presence or absence of suicidal ideation, and the differences in SII and clinicopathological characteristics between the two groups were compared. The optimal critical value of SII and the area under the curve were determined using the subject operating characteristic curve (ROC), and independent risk factors for suicidal ideation were analyzed using binary logistic regression. Results: Patients with MDD with suicidal ideation had higher Hamilton Depression Scale scores, neutrophil, and SII levels compared to those without suicidal ideation (all p < 0.001). The optimal critical SII value was 310.95 (sensitivity = 73.7%, specificity = 44.7%) with an area under the curve of 0.603. In a logistic regression model, SII was significantly associated with suicidal ideation after controlling for age, sex, age at onset, duration of illness, and Hamilton Depression Scale score (β = 0.809, p < 0.001; OR [95% confidence interval] = 2.246 [1.543-3.270]). Conclusion: SII is an independent risk factor affecting suicidal ideation in children and adolescents with MDD.

【Key words】Major depressive disorder; Suicidal ideation; Children and adolescents; Systemic immune-inflammation index