Increased Glutamine in Patients Undergoing Long-term Treatment for Schizophrenia
Year: 2014
Type: article
Study design: Observational Study
Abstract: IMPORTANCE: The N-methyl-d-aspartic acid receptor hypofunction model of schizophrenia predicts a paradoxical increase in synaptic glutamate release. In vivo measurement of glutamatergic neurotransmission in humans is challenging, but glutamine, the principal metabolite of synaptic glutamate, can be quantified with proton magnetic resonance spectroscopy (1H-MRS). Although a few studies have measured glutamate, glutamine, and glutamine to glutamate ratio, it is not clear which of these 1H-MRS indices of glutamatergic neurotransmission is altered in schizophrenia. OBJECTIVE: To examine glutamine, glutamate, and glutamine to glutamate ratio in the dorsal anterior cingulate, as well as their relationships with symptoms and cognition in schizophrenia. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional design using 3-T 1H-MRS in participants recruited from university-based psychiatric outpatient clinics who underwent neuroimaging at an affiliated research facility. Participants were 84 patients with a DSM-IV-TR diagnosis of schizophrenia and 81 psychiatrically healthy volunteers, matched in age, sex, ethnicity, and occupational level to the head of household of family of origin. MAIN OUTCOMES AND MEASURES: Glutamine, glutamate, and glutamine to glutamate ratio. Also symptoms and cognition. RESULTS: Glutamine was increased in the schizophrenia group (P = .01) as well as the glutamine to glutamate ratio (P = .007) but not glutamate (P = .89). Glutamine levels were positively correlated with severity of psychotic symptoms (P = .02). Choline was also increased in schizophrenia (P = .002). CONCLUSIONS AND RELEVANCE: Elevated glutamine, which was directly related to psychotic symptoms, is consistent with increased glutamatergic synaptic release in schizophrenia, as predicted by the N-methyl-d-aspartic acid receptor hypofunction model. Further understanding the underlying mechanism of glutamatergic dysfunction in schizophrenia may lead to new pharmacological strategies to treat psychosis.
Source: JAMA Psychiatry
Authors: Juan R. Bustillo, Hongji Chen, Thomas Jones, Nicholas Lemke, Christopher Abbott, Clifford Qualls, Jose Canive, Charles Gasparovic
Institutions: University of New Mexico, Mind Research Network
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: University of New Mexico Clinical and Translational Science Center, Neural Mechanism of Schizophrenia: Use of Multiple Neuroimaging Tools to Examine, UNM HSC Clinical and Translational Science Center, Brain Glutamate and Outcome in Schizophrenia, University of New Mexico Clinical and Translational Science Center
OpenAlex ID: W2117774616