Neurochemical metabolites in prefrontal cortex in patients with mild/moderate levels in first-episode depression

Abstract

Gülfizar Sözeri-Varma,1 Nalan Kalkan-Oğuzhanoglu,1 Muharrem Efe,1 Yilmaz Kiroglu,2 Taçlan Duman11Department of Psychiatry, 2Department of Radiology, Faculty of Medicine, Pamukkale University, Denizli, TurkeyBackground: Previous studies have determined the neurochemical metabolite abnormalities in major depressive disorder (MDD). The results of studies are inconsistent. Severity of depression may relate to neurochemical metabolic changes. The aim of this study is to investigate neurochemical metabolite levels in the prefrontal cortex (PFC) of patients with mild/moderate MDD.Methods: Twenty-one patients with mild MDD, 18 patients with moderate MDD, and 16 matched control subjects participated in the study. Patients had had their first episode. They had not taken treatment. The severity of depression was assessed by the Hamilton Rating Scale for Depression (HAM-D). Levels of N-acetyl aspartate (NAA), choline-containing compounds (Cho), and creatine-containing compounds (Cr) were measured using proton magnetic resonance spectroscopy (1H-MRS) at 1.5 T, with an 8-cm3 single voxel placed in the right PFC.Results: The moderate MDD patients had lower NAA/Cr levels than the control group. No differences were found in neurochemical metabolite levels between the mild MDD and control groups. No correlation was found between the patients’ neurochemical metabolite levels and HAM-D scores.Conclusion: Our findings suggest that NAA/Cr levels are low in moderate-level MDD in the PFC. Neurochemical metabolite levels did not change in mild depressive disorder. Our results suggest that the severity of depression may affect neuronal function and viability. Studies are needed to confirm this finding, including studies on severely depressive patients.Keywords: major depressive disorder, magnetic resonance spectroscopy, N-acetyl aspartate, creatine, choline