The astroglial protein S100B and visually evoked event-related potentials before and after antidepressant treatment

Rationale: S100B is an astrocytic, calcium-binding protein which in nanomolar concentrations has neuroprotective and regenerating effects on neurons and glial cells. Increased levels have been shown to be positively correlated with therapeutic response in major depression. Event- related potentials ( ERP) have been reported to be impaired in depressed patients. Objectives: The aim of our study was to assess the relationship between S100B and visually evoked ERP in depression. Methods: ERP and S100B serum concentration were studied in 18 patients with major depression, before and after 4 weeks of antidepressant treatment. Results: The S100B concentration in patients was increased at intake and after 4 weeks of treatment compared to healthy controls. Initially increased P3- latency normalized and P2- latency significantly decreased after 4 weeks of treatment, although only in patients with clearly elevated initial S100B levels ( mean plus 2 SD of the healthy controls). Conclusion: The neuroregenerative activity of moderately increased S100B levels in major depression might be a factor contributing to a decrease of prolonged ERP parameters in major depression during antidepressant treatment.