Anterior Cingulate Glutamate Levels Related to Clinical Status Following Treatment in First-Episode Schizophrenia

• Published in: Neuropsychopharmacology (New York, N.Y.) N.Y.), 2012-10, Vol.37 (11), p.2515-2521
• Main Authors: EGERTON, Alice, BRUGGER, Stefan, RAFFIN, Marie, BARKER, Gareth J, LYTHGOE, David J, MCGUIRE, Philip K, STONE, James M
• Format: Article
• Language: English
• Subjects: Adult; Adult and adolescent clinical studies; Antipsychotic Agents - pharmacology; Antipsychotic Agents - therapeutic use; Antipsychotics; Biological and medical sciences; Brain; Cortex (cingulate); Creatine; Creatine - metabolism; Dopamine; Emotional behavior; Female; Glutamatergic transmission; Glutamic acid; Glutamic Acid - metabolism; Gyrus Cinguli - diagnostic imaging; Gyrus Cinguli - drug effects; Gyrus Cinguli - metabolism; Humans; Hypotheses; Linear Models; Magnetic Resonance Spectroscopy; Male; Mass Spectrometry; Medical imaging; Medical sciences; Mental disorders; Metabolites; Neuroimaging; Neuroleptics; Original; Pathophysiology; Protons; Psychiatric Status Rating Scales; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychoses; Psychosis; Psychotropic drugs; Radionuclide Imaging; Remission; Remission (Medicine); Schizophrenia; Schizophrenia - drug therapy; Schizophrenia - pathology; Spectrum analysis; Thalamus; Young Adult
• ISSN: 0893-133X; 1740-634X
• DOI: 10.1038/npp.2012.113

Many patients with schizophrenia show a limited symptomatic response to treatment with dopaminergic antipsychotics. This may reflect the additional involvement of non-dopaminergic neurochemical dysfunction in the pathophysiology of the disorder. We tested the hypothesis that brain glutamate levels would differ between patients with first-episode psychosis who were symptomatic compared with those with minimal symptoms following antipsychotic treatment. Proton magnetic resonance spectroscopy (1H-MRS) spectra were acquired at 3 Tesla in the anterior cingulate cortex and left thalamus in 15 patients with first-episode psychosis in symptomatic remission, and 17 patients with first-episode psychosis who were still symptomatic following at least one course of antipsychotic treatment. Metabolite levels were estimated in ratio to creatine (Cr) using LCModel. Levels of glutamate/Cr in the anterior cingulate cortex were significantly higher in patients who were still symptomatic than in those in remission (T(30)=3.02; P=0.005). Across the entire sample, higher levels of glutamate/Cr in the anterior cingulate cortex were associated with a greater severity of negative symptoms (r=0.42; P=0.017) and a lower level of global functioning (r=-0.47; P=0.007). These findings suggest that clinical status following antipsychotic treatment in schizophrenia is linked to glutamate dysfunction. Treatment with compounds acting on the glutamatergic system might therefore be beneficial in patients who respond poorly to dopaminergic antipsychotics.