MIF and major depressive disorder: Although there is relatively little research on the role of MIF in the development of TD, it is interesting to note that the literature has documented elevated levels of MIF in the peripheral blood in various CNS diseases, such as depression, Parkinson's disease, Alzheimer's disease, multiple sclerosis, and stroke.39, 40, 41, 42, 43 Inácio et al. reported that MIF is part of the signaling network involved in brain plasticity and that elevated levels of MIF in neurons and/or astrocytes can inhibit the recovery of sensory-motor function after stroke.