GFAP and major depressive disorder: Moreover, GFAP decrease has also been confirmed at mRNA and protein levels (Chandley et al., 2013, Fatemi et al., 2004, Johnston-Wilson et al., 2000, Miguel-Hidalgo et al., 2000, Webster et al., 2005) and it is correlated with age and onset of depression: the levels of GFAP protein are indeed significantly lower in less than 60 years-old depressed patients compared to age-matched controls, with no change observed between older MDD subjects and their controls (Si et al., 2004).