S100B serum levels and word memory processing in remitted major depression as reflected by brain potentials

Memory processes, as reflected by 'old/new' effects of event-related potentials (ERPs), have been shown to be impaired in depressed patients. This variability might be partly explained by biological factors. S100B is a glial calcium-binding protein with neuroplastic properties; S100B serum levels have been shown to be increased in depressive patients. The pathophysiologic role of S100B in depression, however, is not yet sufficiently understood.

In the present study, ERPs recorded in a visual continuous word recognition paradigm were therefore investigated in patients with remitted major depression in relation to S100B serum levels.

Patients with moderately increased S100B serum levels (n = 6) showed a normal old/new effect in contrast to a reduced old/new effect in patients with normal S100B levels (n = 6) compared to aged-matched controls.

These findings provide evidence of an association between S100B levels and memory processes in patients with recurrent depression and further suggest a neuroprotective role of moderately increased S100B serum levels in the course of affective disorders.