Factors associated with suicidal ideation in drug-naïve patients with major depressive disorder

Inflammation and immune activation may be involved in the pathological processes of depression, but its role in suicidal ideation (SI) in major depressive disorder (MDD) remains to be elucidated. The present study aims to examine the differences of inflammatory markers between MDD patients with and without SI, and to construct a predictive panel using multi index to distinguish SI in MDD patients.

A total of 151 first-episode drug-naïve MDD patients were recruited for this study. SI was identified using the Chinese Version of Beck Scale for Suicide Ideation (BSI-CV). Based on the results of this scale, the subjects were divided into two groups: MDD with SI (n = 91) and MDD without SI (n = 60). Hamilton Depression Rating Scale-17 (HAMD-17) was used to assess depression symptoms. Plasma concentrations of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), superoxide dismutase (CAT), and superoxide dismutase (SOD) have been measured.

Age (OR = 0.87, 95%CI 0.81-0.93, p < 0.001), HAMD retardation factor score (OR = 1.49, 95%CI 1.18-1.88, p < 0.001), and plasma IL-6 concentration (OR = 1.03, 95%CI 1.00-1.06, p = 0.041) were statistically significant on SI in MDD patients, we constructed a good predictive panel to distinguish SI in patients with MDD by combining age, marital status, HAMD retardation factor score, and plasma IL-6 concentration (AUC = 0.812, p < 0.001).

The study was cross-sectional, making it impossible to determine directionality or causality.

Patients with younger age, single status, serious retardation symptom, and higher plasma IL-6 concentrations are more susceptible to experiencing SI in MDD.