Longitudinal grey-matter and glutamatergic losses in first-episode schizophrenia.

BACKGROUND Progressive volumetric changes in the brains of people with schizophrenia have been attributed to a number of factors. AIMS To determine whether glutamatergic changes in patients with schizophrenia correlated with grey-matter losses during the first years of illness. METHOD Left anterior cingulate and thalamic glutamatergic metabolite levels and grey-matter volumes were examined in 16 patients with first-episode schizophrenia before and after 10 months and 30 months of antipsychotic treatment and in 16 healthy participants on two occasions 30 months apart. RESULTS Higher than normal glutamine levels were found in the anterior cingulate and thalamus of never-treated patients. Thalamic levels of glutamine were significantly reduced after 30 months. Limited grey-matter reductions were seen in patients at 10 months followed by widespread grey-matter loss at 30 months. Parietal and temporal lobe grey-matter loss was correlated with thalamic glutamine loss. CONCLUSIONS Elevated glutamine levels in never-treated patients followed by decreased thalamic glutamine and grey-matter loss in connected regions could indicate either neurodegeneration or a plastic response to reduced subcortical activity.