BDNF and major depressive disorder: Indeed, previous experimental studies have shown alterations of neurodevelopmental, neuroendocrinal and neuroinflammatory factors such as corticotropin-releasing hormone (CRH), interleukin-1β (IL-1β) and brain-derived neurotrophic factor (BDNF) in MS rodents, along with increased anxiety- and depression-related behaviors [6,7,8].