Association of serum glial fibrillary acidic protein, neuron-specific enolase, and S100B with suicidal behaviour in schizophrenia patients: a pilot study

Objectives This pilot study examined the association between serum S100B, neuron-specific enolase (NSE), and glial fibrillary acidic protein (GFAP) and suicidal behaviour in patients with schizophrenia.Methods The study included 233 patients with schizophrenia, divided into groups based on a history of suicide attempts, depressive symptoms, and hopelessness. Clinical symptoms were assessed using PANSS, HDRS‑17, and BHS; protein levels were measured by enzyme‑linked immunosorbent assay.Results Serum S100B levels were elevated in suicide attempters compared to non‑attempters (p = 0.016), but this difference did not survive correction for multiple comparisons (padj = 0.064). Serum GFAP concentrations were elevated in patients with hopelessness (p = 0.001), and this association remained significant after adjustment for multiple comparisons (padj = 0.006) and was independent of confounders in multiple linear regression analysis (β = 0.360, p = 0.001). In patients with both suicide attempts and hopelessness, S100B and GFAP were elevated (p = 0.027 and p = 0.001, respectively); however, after correction, only GFAP remained significant (padj = 0.006).Conclusions Serum GFAP levels are associated with hopelessness in schizophrenia. Unchanged NSE levels suggest no neuronal loss accompanying glial changes. However, the pathogenetic mechanisms of the findings require further investigation.