Association of interleukin-6 (IL-6) with suicide attempt

Background: Suicide is a major cause of death among young adults, but few biological markers have been linked to suicidality. Interleukin-6 (IL-6) may play a role in elevating the risk of depression and suicidal tendencies. However, limited research has explored the connections between IL-6 and suicidal thoughts or actions. Aim: This study was conducted to investigate the association between IL-6 levels and suicide attempts. Materials and Methods: In this observational study, 31 patients undergoing clinical follow-up after a suicide attempt were enrolled. The Columbia Suicide Severity Rating Scale (C-SSRS) was used for assessment of suicidal behavior. IL-6 levels in patients were measured using the ELISA technique with the IL-6 Human ELISA Kit (Invitrogen, Cat. No-BMS213-2) following the manufacturer’s protocols. Results: The mean level of IL-6 in the patients was 2.75 ± 6.50 (range: 0–36.6) pg/mL. Women exhibited higher IL-6 levels than men (women = 4.04 ± 8.97; men = 1.54 ± 1.86) pg/mL. IL-6 levels significantly increased with higher severity levels of suicidal ideation, with a P value of 0.0001, indicating a positive association. A significant positive correlation was observed between IL-6 levels and the intensity of suicidal ideation, with higher intensity associated with elevated IL-6 levels ( P value = 0.0113). A significant positive correlation was observed between IL-6 levels and the lethality of suicidal ideation, with higher levels of lethality associated with elevated IL-6 levels ( P value = 0.0129). Conclusion: This study provides evidence that elevated IL-6 levels are associated with suicide attempts, supporting its potential role as a biomarker for suicidal behavior.