Increased myo-inositol in the posterior cingulate cortex in first-episode major depressive patients

Abstract

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 1 H-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.

Metabolic Fingerprints of Effective Fluoxetine Treatment in the Prefrontal Cortex of Chronically Socially Isolated Rats: Marker Candidates and Predictive Metabolites

“…Although differential MI content has been reported depending on the model species and brain regions [ 49 , 50 , 51 , 52 ] or age [ 53 , 54 , 55 ], MI has been suggested as a metabolic marker for depression [ 56 ]. In line with this, the classical ROC analysis in our study identified MI as the best candidate to discriminate CSIS from controls.…”

Neural correlations between cognitive deficits and emotion regulation strategies: understanding emotion dysregulation in depression from the perspective of cognitive control and cognitive biases

“…Substantial evidence suggests that the processes of seeking and extracting information from autobiographical memory are linked to over-recruitment of the PCC regions (Leech & Sharp, 2014 ). Several studies have also shown that pathological rumination and attentional self-focusing in depression is governed by the activity pattern of PCC (Cheng et al ., 2018 ; Granados-Domínguez et al ., 2013 ). The abnormal activity in the sgPFC may reflect a maladaptive pattern of self-referential thought with rumination that is associated with a heightened risk of depression and other mental illnesses.…”