Objective: S100B, which is a member of S100 proteins, is the major neurotropic factor of serotonergic neurons, and it has such duties as synaptic plasticity, new neuron formation and axon germination. The micromolar concentrations of extracellular S100B induce apoptosis and neurodegeneration, whereas nanomolar concentrations make neurit grow and maintain the survival of the neuron during the growth. The aim of this study was to examine the probable relationship between S100B levels in the patients with major depression and panic disorder and the diagnosis and treatment of the diseases.

Material and Method: 34 patients recently-diagnosed with major depression, 33 patients recently-diagnosed with panic disorders and 33 the healthy control group demographically similar to each other were included. Our patient groups were chosen from the ones whose Beck Depression and Beck Anxiety inventories are >16, while the control group was chosen from the ones whose Beck Depression and Beck Anxiety inventories are <13. Serum S100B (Electrochemiluminescence Immunoassay, Roche Elecsy 2010) and calcium (Colorimetric Endpoint Methot, Roche Modular) ranges of the patient groups were measured in pre-treatment and post-treatment with a month-selective serotonin reuptake inhibitors (SSRI).

Results: Whenwecomparecasesamongthegroups, S100B mean levels of the major depression group (0.056±0.025 µg/L) (0.052 [0.02-0.16]) and the panic disorder group (0.064±0.045 µg/L) (0.0545 [0.03-0.28]) are higher
than S100B level of the control group (0.046±0.020 µg/L) (0.044 [0.024-0.097]) (p<0.05). Before and after the treatment, any significant changes in S100B levels both of the major depression and the panic disorder groups were not found (p=0.173; p=0.777; respectively)

Conclusion: S100B levels are significantly higher in the patients with major depression and panic disorder than the control group. Therefore, S100B levels can be biological markers for mood disorders (depression, anxiety).

S100B Calcium levels Major depression Panic disorder