Author(s)

Lily Magally Granados-Domínguez, Enrique O. Flores-Gutiérrez, Sarael Alcauter, Juan José Cervantes, Marina Torres-Álvarez, María Corsi-Cabrera

Laboratory for Sleep Research, Faculty of Psychology, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.
Sub-Department of Clinical Investigations, Instituto Nacional de Psiquiatría Ramón de la Fuente Mu?íz, Mexico City, Mexico.

Major depressive disorder (MDD) is a severe, disabling pathology characterized, in addition to affective, cognitive and motor symptoms, by self-focused attention and rumination. During recursive self-focused processes and rumination, the posterior cingulate cortex (PCC) is activated. In vivo proton magnetic resonance spectroscopy (MRS) is a noninvasive imaging technique that can directly assess living biochemistry in localized brain regions. The aim of this study, therefore, was to use ¹H-MRS as a means of analyzing brain metabolites in the PCC of a group of first-episode, unmedicated MDD patients. PCC metabolite levels were analyzed at 3-T in a single voxel located bilaterally over the PCC in 7 patients diagnosed for the first time with MDD and with no previous pharmacological treatment, as well as in 9 control subjects. Differences in metabolite levels between groups were compared using independent t-tests. Myo-inositol was significantly higher, and NAA + NAAG/Cr significantly lower, in MDD patients than in controls. The other brain metabolites showed no statistical differences. The present results suggest that alterations in PCC metabolite levels are likely involved in MDD pathophysiology, and may help to improve our understanding of MDD and the role of the PCC in some symptoms of depression.

Major Depressive Disorder; Posterior Cingulate Cortex; Metabolites; ¹H-MRS; Myo-Inositol; N-Acetyl-Aspartate

Granados-Domínguez, L. , Flores-Gutiérrez, E. , Alcauter, S. , Cervantes, J. , Torres-Álvarez, M. and Corsi-Cabrera, M. (2013) Increased myo-inositol in the posterior cingulate cortex in first-episode major depressive patients. Advances in Bioscience and Biotechnology, 4, 45-52. doi: 10.4236/abb.2013.46A007.