Abstract

Background
The duration of untreated psychosis (DUP) is a factor associated with the natural course of schizophrenia and an independent predictor of treatment outcome. Recent studies focus on the effects of DUP on the functioning of the nervous system, but the findings are inconsistent. As proton magnetic resonance spectroscopy (1H-MRS) enables the assessment of signals from chemical compounds in vivo, it seems a useful tool to explore this problem.
Material and Method
In this study the relationships between DUP and 1H-MRS measurements were investigated. Thirty patients with first-episode schizophrenia and 19 controls were examined. Median DUP was 10 weeks. Voxels were positioned in the following regions of interest: the left frontal lobe, left temporal lobe, and left thalamus. The ratios of N-acetylaspartate (NAA), choline-containing compounds (Cho), myoinositol (mI), and glutamate/glutamine/GABA complex (Glx) to creatine (Cr) and the non-suppressed water signal were determined.
Results
There were no significant differences between the whole group of patients and healthy subjects for the analyzed metabolite ratios in any region of interest. No differences were found between the groups of patients with short and long DUP and controls. No significant correlation was observed between DUP and metabolite ratios.
Conclusions
The results of the study may suggest that the relatively short DUP does not influence brain metabolism in first-episode schizophrenia.

Keywords: Psychotic Disorders - complications, Schizophrenia - metabolism, Time Factors, Magnetic Resonance Spectroscopy, Frontal Lobe - pathology, Demography, Case-Control Studies