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Defining the disturbance in cortical glutamate and GABA function in psychosis and its origins and consequences

Deakin, Bill; Liddle, Elizabeth; Rathnaiah, Mohanbabu; Gregory, Cathy; Katshu, Mohammad; Wiliams, Gemma; Conen, Silke; Smallman, Richard; Koelewijn, Loes C.; Anton, Adriana; Kumar, Jyothika; Gasgoyne, Lauren E.; Chen, Chen; Nikkheslat, Naghmeh; Evans, John; Lanz, Bernard; Walters, James; Talbot, Peter; Palaniyappan, Lena; Singh, Krish D.; Morris, Peter; Williams, Steven R.; Liddle, Peter F.

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Authors

Bill Deakin

Mohanbabu Rathnaiah

Cathy Gregory

Gemma Wiliams

Silke Conen

Richard Smallman

Loes C. Koelewijn

Adriana Anton

Jyothika Kumar

Lauren E. Gasgoyne

Chen Chen

Naghmeh Nikkheslat

John Evans

Bernard Lanz

James Walters

Peter Talbot

Lena Palaniyappan

Krish D. Singh

Peter Morris

Steven R. Williams

Peter F. Liddle



Abstract

It is widely thought that the onset of psychotic symptoms in schizophrenia may arise from an early neurotoxic phase, possibly related to oxidative stress or inflammation, and a late residual damage phase associated with persistent negative symptoms. We tested this hypothesis in a 3-centre study using magnetic resonance spectroscopy (MRS) to determine whether abnormalities in glutamate, glutamine and GABA content in anterior cingulate cortex (ACC) differed between people with minimally treated ‘Recent’ onset schizophrenia and an ‘Established’ group with > 10 years of treatment. We tested whether neurochemical abnormalities were i) mediated by raised circulating inflammatory cytokine concentrations, c-reactive protein (CRP) and interleukin-6 (IL-6), or depletion of glutathione and ii) associated with ratings of positive and negative symptoms. Relative to age-matched controls, the Established group showed significantly greater reduction in ACC glutamate than the Recent group, which did not differ from controls. This effect was not attributable to antipsychotic drug exposure. Patient ACC glutathione was negatively correlated with age. IL-6 was increased in both clinical groups, while increases in CRP were greater in the Established than Recent group. Elevated CRP was entirely accounted for by greater antipsychotic drug exposure and BMI, while residual elevation in IL-6 in the Established group did not account for their lower ACC glutamate. GABA was reduced relative to controls across ACC and occipital voxels. This reduction was not associated with drug treatment, BMI or cytokine levels. Only ACC GABA content correlated significantly with symptoms, lower content with greater positive and negative symptoms across both groups.

Citation

Deakin, B., Liddle, E., Rathnaiah, M., Gregory, C., Katshu, M., Wiliams, G., Conen, S., Smallman, R., Koelewijn, L. C., Anton, A., Kumar, J., Gasgoyne, L. E., Chen, C., Nikkheslat, N., Evans, J., Lanz, B., Walters, J., Talbot, P., Palaniyappan, L., Singh, K. D., …Liddle, P. F. Defining the disturbance in cortical glutamate and GABA function in psychosis and its origins and consequences

Working Paper Type Working Paper
Deposit Date Jul 3, 2024
Publicly Available Date Jul 8, 2024
Public URL https://nottingham-repository.worktribe.com/output/36579859
Publisher URL https://www.medrxiv.org/content/10.1101/2024.06.26.24308831v1