However, studies on the effects of BDNF and other mediators on brain plasticity [93], protection of the hippocampus, and plausible neurobiological adaptations to strength training are lacking [24,84], as well as the role that IGF-1 would have on psychosocial parameters [74,75,76,85,86] since IGF-1 remains ambiguous for the treatment and diagnosis of depression [75,78] over other markers [94]. Here, BDNF is linked to major depressive disorder.