Sodium Benzoate May Improve Symptoms, Cognition in Schizophrenia, Study Suggests

Sodium benzoate—commonly used as a food preservative—appears to improve symptoms and cognition in schizophrenia when used as an adjunct to antipsychotic medication therapy, according to an online report in JAMA Psychiatry by American and Taiwanese researchers. They conducted a randomized, double-blind, placebo-controlled trial of 52 patients with chronic schizophrenia who had been stabilized with antipsychotic medications for three months or longer. Patients were given either six weeks of add-on treatment of 1 g/d of sodium benzoate or placebo.

Adding benzoate produced a 21% improvement in Positive and Negative Syndrome Scale (PANSS) scores, as well as improvement in neurocognition, including information-processing speed and visual learning, compared with subjects receiving placebo. Benzoate was well tolerated without significant adverse effects.

Benzoate blocks the metabolism of d-amino acids, which in turn enhances the function of the NMDA receptor in the brain; NMDA is believed to be vital to cognition, a crucial symptom domain of schizophrenia. “The preliminary results show promise for d-amino acid oxidase inhibition as a novel approach for new drug development for schizophrenia,” the authors said.

For more information on research into cognition in schizophrenia, see "Neuropsychological Decline in Schizophrenia From the Premorbid to the Postonset Period" in AJP in Advance.

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