The results of a 7T MRS study of a large cohort of patients with a first episode of psychosis (FEP) and healthy control subjects (HC) are reported. In patients with FEP, significant reductions in the neurotransmitters glutamate and GABA were found in selected gray matter regions, and the neuromodulator NAAG was reduced in white matter. Other metabolic abnormalities were reduced NAA (suggesting neuroaxonal damage) and glutathione. Metabolite differences were also found to depend on diagnosis. This study suggests that 7T MRS is a useful modality for understanding the molecular pathophysiology of psychosis.