Relationship of Auditory Electrophysiological Responses to Magnetic Resonance Spectroscopy Metabolites in Early Phase Psychosis

This project aimed to examine the relationship between the concentrations of various neural metabolites (labeled Cre, mI, NAA, GPCPCH, and GluGln in the attached dataset) measured via magnetic resonance spectroscopy (MRS) and two event related potentials, including amplitude of the mismatch negativity (MMN; labeled FZMMNvoltage in the attached dataset) and power of the auditory steady state response (ASSR; labeled FZ40Hzpower in the attached dataset) to 40 Hz click stimuli in individuals with early phase psychosis (EPP). Group differences in metabolite concentrations, MMN amplitude, and 40 Hz ASSR power were also compared relative to healthy control participants. Demographic (age, sex), cognitive (from the Brief Assessment of Cognition in Schizophrenia, BACS composite), and symptom data (from the Positive and Negative Syndrome Scale, PANSS) is also available. Key findings included elevated concentration of several metabolites in individuals with EPP (i.e., Glx, Cre, Cho) relative to controls, and no difference in MMN amplitude or 40 Hz ASSR power. In individuals with EPP, increased metabolite levels were associated with smaller MMN amplitude. A weaker association between increased metabolite levels and 40 Hz ASSR power was found. Neither the MRS metabolites nor electrophysiological measures were correlated with symptom severity, age, cognitive function, or medication dosage.