Magnetic Resonance Imaging Studies In Single-episode, Medication-naive Subjects With Major Depressive Disorder

ObjectiveDepression is the most popular kind of psychiatric disorder. It has a higher recurrent rate and lifetime morbidity. There is growing evidence that pathophysiology of depression is associated with impairments of brain network. Convergent studies have implicated grey matter and white matter abnormalities in the pathophysiology of major depressive disorder (MDD). In this study, structure magnetic resonance imaging (sMRI) and diffusion tensor imaging (DTI) was used to examine grey matter and white matter abnormalities in single-episode, medication-naive MDD participants.MethodssMRI and DTI data were acquired from 35 MDD and 35 healthy control participants. A voxel-based analysis was used to investigate whole brain grey matter and white matter abnormalities in the MDD group.Results1,LES,HAMD and HAMA scores were significantly increased in the MDD group compared to the healthy group. LES scores were significantly increased in the longer illness duration MDD group compared to the shorter illness duration MDD group.2,Grey matter volume was significantly decreased in the frontal lobe, parietal lobe and posterior cingulated in the MDD group compared to the healthy group. Grey matter volume was significantly decreased in the parietal lobe in the longer illness duration MDD group compared to the shorter illness duration MDD group.3,Fractional anisotropy was significantly decreased in the superior longitudinal fasciculus (SLF) within the frontal lobe, frontal and parietal white matter in the MDD group compared to the healthy group. Fractional anisotropy was significantly decreased in the parietal lobe in the longer illness duration MDD group compared to the shorter illness duration MDD group.Conclusion1. The quantity of negative life events especially family life events was associated with the single depressive episode. There was more negative life events appeared in the MDD patients with longer illness duration than shorter illness duration, which means the increment of negative stress events may due to the delay of diagnosis and treatment.2. Our results demonstrate abnormalities with grey and white matter in several brain regions in the single-episode, medication-naive MDD patients and suggest that these abnormalities may play a key role in the pathophysiology of MDD.