Inflammatory Biomarkers in Acute Suicidal Behaviors

Area of Science:

• Neuroscience
• Psychiatry
• Immunology

Background:

• Major depressive disorder (MDD) poses significant suicide risk.
• Current suicide risk assessment relies heavily on subjective clinical evaluation.
• Immune-inflammatory dysregulation is increasingly recognized as a biological link between depression and suicidality.

Purpose of the Study:

• To review current findings on inflammatory biomarkers as potential predictors of suicidal behavior in MDD.
• To explore the role of immune-inflammatory markers in the pathophysiology of suicidality.
• To assess the clinical utility of these biomarkers in suicide risk assessment.

Main Methods:

• Systematic review of studies investigating inflammatory biomarkers in suicidal individuals with MDD.
• Analysis of acute phase proteins (e.g., C-reactive protein, homocysteine).
• Evaluation of hematological indices (e.g., NLR, PLR) and cytokines (e.g., IL-6, TNF-α, IL-1β, IL-4, IL-10).

Main Results:

• Elevated levels of CRP, IL-6, TNF-α, and IL-1β, and decreased levels of IL-4 and IL-10 are frequently reported in suicidal individuals.
• These findings suggest an imbalance in the immune-inflammatory response system (IRS) and compensatory immune-regulatory reflex system (CIRS).
• Hematological ratios present accessible, cost-effective indicators, but study heterogeneity and confounders limit current clinical utility.

Conclusions:

• Inflammatory biomarkers show potential as objective adjuncts to subjective clinical judgment in suicide risk assessment for MDD.
• Immune-inflammatory dysregulation, potentially via the kynurenine pathway, may contribute to neuroinflammation and neurotoxicity in suicidality.
• Further standardization and validation are needed to integrate these biomarkers into routine clinical practice.