Abstract
Background: Converging lines of evidence suggest that glutamatergic dysfunction may contribute to the pathophysiology of first episode psychosis. We aimed to investigate whether first episode psychosis patients free from all pharmacological treatments and illicit substances show cortical glutamatergic alterations.
Method: One-hundred and eleven volunteers including 65 healthy volunteers and 46 first episode psychosis patients free from all pharmacological treatments (28 drug naïve) underwent a proton magnetic resonance spectroscopy scan measuring glutamate levels in the bilateral anterior cingulate cortex. Symptom severity was measured using the Positive and Negative Syndrome Scale (PANSS) and cognition was measured using the Wechsler Adult Intelligence Scale (WAIS) digit symbol test.
Results: There were no differences between patients and controls for glutamate (F(1,109)=0.171, p=0.680), glutamine (F(1,50)=0.267, p=0.608),GLX (F(1,110)=1.923, p=0.168) or NAA (F(1,106)=0.950, p=0.332). These findings remained unchanged when adjusting for the effects of age, sex and ethnicity or when restricting the analyses to patients who were both medication naïve to all pharmacological treatments and illicit substances. There were no relationships between glutamate levels and symptom severity or cognitive function.
Conclusions: Relative to healthy volunteers, drug-free first episode psychosis patients free from illicit substances show no evidence of metabolite alterations in the anterior cingulate cortex. These findings remained unchanged when investigating patients who were medication naïve to all pharmacological treatments. Whilst these findings do not preclude glutamatergic alterations in first episode psychosis, methodological advances are needed to investigate whether patients show alterations in other aspects of glutamate function, such as pre-synaptic glutamate or release.
Method: One-hundred and eleven volunteers including 65 healthy volunteers and 46 first episode psychosis patients free from all pharmacological treatments (28 drug naïve) underwent a proton magnetic resonance spectroscopy scan measuring glutamate levels in the bilateral anterior cingulate cortex. Symptom severity was measured using the Positive and Negative Syndrome Scale (PANSS) and cognition was measured using the Wechsler Adult Intelligence Scale (WAIS) digit symbol test.
Results: There were no differences between patients and controls for glutamate (F(1,109)=0.171, p=0.680), glutamine (F(1,50)=0.267, p=0.608),GLX (F(1,110)=1.923, p=0.168) or NAA (F(1,106)=0.950, p=0.332). These findings remained unchanged when adjusting for the effects of age, sex and ethnicity or when restricting the analyses to patients who were both medication naïve to all pharmacological treatments and illicit substances. There were no relationships between glutamate levels and symptom severity or cognitive function.
Conclusions: Relative to healthy volunteers, drug-free first episode psychosis patients free from illicit substances show no evidence of metabolite alterations in the anterior cingulate cortex. These findings remained unchanged when investigating patients who were medication naïve to all pharmacological treatments. Whilst these findings do not preclude glutamatergic alterations in first episode psychosis, methodological advances are needed to investigate whether patients show alterations in other aspects of glutamate function, such as pre-synaptic glutamate or release.
| Original language | English |
|---|---|
| Article number | 8685 |
| Number of pages | 1 |
| Journal | Scientific Reports |
| Volume | 9 |
| Issue number | 1 |
| Early online date | 2 Jul 2019 |
| DOIs | |
| Publication status | Published - 2 Jul 2019 |