Increased Hippocampal Glutamate and Volumetric Deficits in Unmedicated Patients With Schizophrenia

Glutamatergic and Neuronal Dysfunction in Gray and White Matter: A Spectroscopic Imaging Study in a Large Schizophrenia Sample

“…Although not systematically evaluated, other studies with smaller samples have failed to detect abnormalities in dorsal regions. 7,35,[57][58][59] Also, several studies suggest that glutamatergic increases may be more robust in ventral brain regions 23,24,[33][34][35][60][61][62] with effect sizes larger than here reported. We are currently implementing a whole-brain 1 H-MRSI sequence.…”

“…34 Following a 4-week treatment the elevation was only 6% (not statistically significant, with N = 40). The short-term longitudinal studies 33,34 strongly support that antipsychotic treatment has a normalizing (reducing) effect on Glx. However, our findings support that at least in more dorsal medial frontal cortex, a small increase in Glx persists, despite antipsychotic treatment, suggesting a trait effect.…”

“…Two 33,34 of the 5 recent studies documenting elevations involved more ventral regions. Of particular interest are studies in unmedicated patients which consistently report higher Glx (in striatum, 34 hippocampal 33 and medial frontal regions 35 ) and normalization with antipsychotic treatment. We previously reported increased glutamine but normal glutamate in the dorsal anterior cingulate.…”

“…[26][27][28][29][30] However, the quality of the spectral fits is not always clear in these reports (except for [27][28][29] ) and the samples were small (9 to 30 for the schizophrenia groups 6 ). More recent studies reported increases, [31][32][33][34][35] reductions 25,[36][37][38] and no differences 39 in Glx or glutamate. Two 33,34 of the 5 recent studies documenting elevations involved more ventral regions.…”

“…More recent studies reported increases, [31][32][33][34][35] reductions 25,[36][37][38] and no differences 39 in Glx or glutamate. Two 33,34 of the 5 recent studies documenting elevations involved more ventral regions. Of particular interest are studies in unmedicated patients which consistently report higher Glx (in striatum, 34 hippocampal 33 and medial frontal regions 35 ) and normalization with antipsychotic treatment.…”