Evidence map›Paper›PMID 42310607›Full record

ArticleBMC psychiatry2026

Glutamate change in the anterior cingulate cortex after starting clozapine: evaluating 1H-MRS pilot data.

Maxwell Seward, Esther Puiras, Candice E Crocker, Philip G Tibbo, Temi Toba Oluboka, Derek J Fisher, Kara Dempster

Abstract read
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Article in BMC psychiatry, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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No citing paper in PubMed yet.

4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Maxwell SewardDepartment of Psychiatry, Dalhousie University, Halifax, NS, Canada.
Esther PuirasNova Scotia Health Authority, Halifax, NS, Canada.
Candice E CrockerDepartment of Psychiatry, Dalhousie University, Halifax, NS, Canada.
Philip G TibboDepartment of Psychiatry, Dalhousie University, Halifax, NS, Canada.
Temi Toba OlubokaNova Scotia Health Authority, Halifax, NS, Canada.
Derek J FisherDepartment of Psychiatry, Dalhousie University, Halifax, NS, Canada.
Kara DempsterDepartment of Psychiatry, Dalhousie University, Halifax, NS, Canada. kara.dempster@nshealth.ca.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

background30% of individuals with schizophrenia do not respond to first line dopamine-blocking antipsychotic medications and meet criteria for treatment resistant schizophrenia (TRS). Elevated glutamate levels in the anterior cingulate cortex (ACC) have been found to be associated with poor response to dopamine-blocking antipsychotics in early phase psychosis (EPP). Clozapine is the gold standard treatment for TRS with some evidence suggesting that clozapine may work in part through altering glutamate neurotransmission. However, the exact mechanisms through which clozapine is effective for TRS remain largely unclear and require further investigation.

objectiveTo our knowledge, this is the first study to investigate glutamatergic changes after 6 months of clozapine treatment in patients with EPP. We hypothesized that there would be a decrease in glutamate concentration after 6-months of clozapine treatment.

methodTreatment resistant EPP patients were recruited for a larger neuroimaging study; 7 individuals who met criteria for TRS underwent measurement of ACC glutamate prior to starting clozapine, and following clozapine treatment for 6 months. 1H-MRS acquisitions were performed using Point Resolved Spectroscopy in the bilateral dorsal ACC.

resultsOne case was excluded from imaging analyses due to poor MRS quality (Signal to noise ratio within LCmodel < 12). Paired sample t-test found a non-significant decrease in average glutamate concentration in the ACC 6 months after starting clozapine, (6) = 0.49, p = .647, 95% CI [- 2.72, 4.00]; however, a small effect size was detected (d = 0.34, 95% CI [-0.81, 1.47]).

conclusionsWhile there was not a significant change in glutamate in the ACC 6 months after starting clozapine, declining glutamate with a low-moderate effect size is aligned with the hypotheses and may inform future studies. This work suggests that future studies are warranted using a larger sample size. CLINICAL TRIAL NUMBER: Not applicable.

Indexed as

Antipsychotic AgentsClozapineGlutamic AcidGyrus CinguliPsychotic DisordersSchizophreniaSchizophrenia, Treatment-ResistantAdultFemaleHumansMalePilot ProjectsProton Magnetic Resonance SpectroscopyYoung AdultAntipsychotic AgentsClozapineGlutamic AcidAnterior cingulate cortexClozapineGlutamateMagnetic resonance spectroscopyTreatment resistant schizophrenia

Identifiers

PMID42310607
PMCPMC13508457

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.