Data are mixed regarding diagnostic specificity, e.g., decreased GFAP expression in the amygdala of individuals with MDD, but not those with bipolar disorder (BD) (Altshuler et al. 2010), and in the cerebellum of individuals with MDD but not those with schizophrenia (Fatemi et al. 2004). Another report identified dlPFC layer-specific GFAP reductions in individuals with schizophrenia compared to healthy controls (Rajkowska et al. 2002). In addition, there is increased GFAP expression in subcortical brain structures in schizophrenia and MDD relative to non-psychiatric controls (Barley et al. 2009). Finally, serum levels of glial-derived S100β are increased in MDD, and these levels are not affected by antidepressant treatment (Schroeter et al. 2008). The preponderance of the above evidence, at the very least, suggests astrocytic dysfunction in the MDD brain.
