Alterations of cerebral glutamate in the euthymic state of patients with bipolar disorder

Differential neurometabolite alterations in brains of medication‐free individuals with bipolar disorder and those with unipolar depression: a two‐dimensional proton magnetic resonance spectroscopy study

“…reported higher levels of Glx and Glu in the ACC of patients with BD; similarly, the BD group showed higher ratios of Glu/Cr and Glx/Cr in the ACC voxel compared with HCs in a recent study . In a more recent study, Glu concentrations were significantly increased in the ACC of euthymic outpatients with BD . In addition, increased levels of Glu were observed in the frontal cortex, hippocampus, and left thalamus .…”

“…26 In a more recent study, Glu concentrations were significantly increased in the ACC of euthymic outpatients with BD. 27 In addition, increased levels of Glu were observed in the frontal cortex, 28 hippocampus, 29 and left thalamus. 16 Together, the increased levels of Glx and/or Glu found in various brain regions of patients with BD in previous studies and the increased levels of Glx, of which Glu is the major constituent (as indicated by the Glu/Gln ratio being in the range from 2.4 to 3.8 in vivo 30 ), in patients with BD found in the present study suggest the presence of an increased excitatory amino acid signal in the brains of these patients.…”

A pilot open series of lamotrigine in DBT-treated eating disorders characterized by significant affective dysregulation and poor impulse control

“…Our findings raise the question as to whether glutamatergic abnormalities play a role in affective and behavioral dysregulation in individuals with eating disorders as they may in bipolar disorder and BPD [72, 73]. This could help explain why traditionally-used serotonergic antidepressant monotherapy has limited impact for many patients with AN-BP- and BN-spectrum disorders.…”

Glutamate and Gamma-Aminobutyric Acid Systems in the Pathophysiology of Major Depression and Antidepressant Response to Ketamine

“…In comparison to healthy subjects, aberrant amino acid neurotransmitter levels measured by 1 H-MRS have been found in individuals with MDD (6, 17–19) and BD (20, 21). Specifically, in MDD patients, Glu and Glx reductions were found in the dorsolateral prefrontal cortex (dlPFC) (22) and other prefrontal cortical (PFC) areas such as the dorso-medial and dorso-anterolateral PFC (23) and anterior cingulate cortex (ACC) (24), with increased levels in the occipital cortex (OCC) (25) to a degree that may be related to duration of illness (26).…”

“…Although some studies found no differences in Glu between BD patients and healthy subjects (28–31), two meta-analyses of 1 H MRS studies in BD noted increased Glx in the PFC regardless of mood state, as well as in the ACC in depressed states (20, 32). A recent study showed that elevated Glu in the ACC associated with BD patients in euthymic states was related to number of depressive/manic episodes (21); notably, this finding may allow for differentiation of depression between BD and MDD. Impaired oxidative metabolism in glutamatergic neurons has been hypothesized to explain elevated Glx and lactate levels associated with mixed or depressed states in BD (33), and further supports a contributory role of inflammation in the pathophysiology of depression (34).…”