Table of Contents Author Guidelines Submit a Manuscript
Neural Plasticity
Volume 2013 (2013), Article ID 873278, 7 pages
Review Article

Neurobiology of Major Depressive Disorder

Servicio de Psiquiatría, Hospital Universitario La Paz, 28046 Madrid, Spain

Received 16 August 2013; Accepted 11 September 2013

Academic Editor: Michel Baudry

Copyright © 2013 Rosa Villanueva. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We survey studies which relate abnormal neurogenesis to major depressive disorder. Clinically, descriptive gene and protein expression analysis and genetic and functional studies revised here show that individual alterations of a complex signaling network, which includes the hypothalamic-pituitary-adrenal axis; the production of neurotrophins and growth factors; the expression of miRNAs; the production of proinflammatory cytokines; and, even, the abnormal delivery of gastrointestinal signaling peptides, are able to induce major mood alterations. Furthermore, all of these factors modulate neurogenesis in brain regions involved in MDD, and are functionally interconnected in such a fashion that initial alteration in one of them results in abnormalities in the others. We highlight data of potential diagnostic significance and the relevance of this information to develop new therapeutic approaches. Controversial issues, such as whether neurogenesis is the basis of the disease or whether it is a response induced by antidepressant treatments, are also discussed.