Association between C-reactive protein and suicidal behavior in an adult inpatient population

To examine the relationship of inflammation and suicidal behavior in hospitalized adult psychiatric patients.

We retrospectively examined serum high sensitivity C-reactive protein (hsCRP) levels in inpatients at a tertiary-level university hospital (N = 184). The inpatients comprised three cohorts: 1) patients admitted following a suicide attempt, 2) patients with suicidal ideation, and 3) inpatient psychiatric controls. Additionally, we gathered demographic data, clinical data, smoking status, white blood cell count, and fasting lipid panel.

As CRP level increased, the probability of patients belonging to the suicide attempt group increased as compared to both the probabilities of being in inpatient psychiatric control and or suicide ideation groups [OR = 2.09, CI = (1.29, 3.38) and OR = 1.75, CI = (1.15, 2.66) respectively]. We also observed a significant effect of depression in that depressed patients were more likely to have a suicide attempt when compared to patients with no depression or with mania [OR = 10.38, CI = (1.97, 54.70)].

There seems to be an inflammation gradient, measured by CRP levels, from recent suicide attempters, suicidal ideators and psychiatric controls. We replicated the association between a pro-inflammatory state and suicidal behavior in a sample of "real world" severely ill psychiatric inpatients.