1H MRS Provides Evidence of Altered Frontal Cortex GABA & Glutamate-Glutamine in Schizophrenia In Vivo

Lawrence S. Kegeles^1,2, Xiangling Mao³, Arielle Stanford¹, Najate Ojeil¹, Beatriz Alvarez¹, Ragy R. Girgis¹, Roberto Gil¹, Anissa Abi-Dargham^1,2, Sarah H. Lisanby¹, Dikoma C. Shungu³

We used proton MRS to evaluate GABA and glutamate-glutamine (Glx) levels in frontal cortex in schizophrenia, an illness in which postmortem studies suggest frontal cortex GABA deficits. In the anterior cingulate but not the dorsolateral prefrontal cortex, we instead found elevations in GABA and Glx in unmedicated patients compared to controls and medicated patients. These findings are opposite to the deficits found in major depression. They also suggest that antipsychotic medications may lower frontal GABA and glutamate to the normal range. These results are discussed in relation to postmortem GABA data and the NMDA receptor hypofunction hypothesis of schizophrenia.