Clinical studies on EPO in chronic brain diseases (schizophrenia, multiple sclerosis, major depression and bipolar disorder) with extended treatment using high-dose EPO over many weeks showed consistently advantageous effects on cognition, motor function, and even reduction of brain matter loss (Ehrenreich et al. 2007a; Ehrenreich et al. 2007b; Miskowiak et al. 2014a; Miskowiak et al. 2014b; Miskowiak et al. 2015; Wustenberg et al. 2011). Here, EPO is linked to major depressive disorder.