Resting-state Functional MRI Study On Mood Disorder

Neuropsychiatric diseases have dramatically threatened our families and society due to the prevalence of such diseases. Among them, Major Depressive Disorder (MDD) and Bipolar Disorder (BD), two subtypes of mood disorder, are both characterized by significant and lasting changes in mood. Due to the similarity of the two diseases, depending on clinical scores and subjective experience of psychiatrists may leads to misdiagnosis and delayed treatment. However, accurate and effective biomarkers of prediction and early diagnosis for MDD and BD have not yet be found. This study investigated the difference of functional connectivity pattern in the brain of MDD patients, BD patients and normal subjects (HC) using resting-state functional magnetic resonance imaging (fMRJ) techniques, thus, aimed to explore some underlying objective neuroimaging biomarkers for prediction and early diagnosis of the two diseases.In this paper, the main research progress and achievements include:1) We classified and preprocessed the collected resting-state fMRI data of MDD, BD and HC, extracted the three sub-regions (centromedial nucleus, CM; laterobasal nucleus, LB; superficial nucleus, SF) of amygdala, which play an important role in mood regulation, according to the its cytoarchitecture, and analyzed the functional connectivity between the three regions of interest (ROT) and whole brain, respectively. We found that compared to MDD patients, the functional connectivity of dorsolateral prefrontal cortex, sensorimotor area and inferior temporal gyms as well as temporal pole significantly increase in BD patients, while the functional connectivity of rostral prefrontal cortex, posterior lateral parietal lobe and cerebellum significantly decrease, especially in CM sub-regions. The discovery may be of importance to the discrimination of MDD and BD.2) We used FreeSurfer to calculate the cortical thickness and surface area for each subject and found a region, named right medial superior frontal gyrus (rSFGmed), with significant difference between MDD and BD. Then, we analyzed the functional connectivity between this region and whole brain, found increased functional connectivity in left temporal pole in BD compared to MDD, increased functional connectivity in bilateral superior frontal gyrus in BD compared to HC, and increased functional connectivity in left paracentral lobule, precuneus and postcentral gyrus in MDD compared to HC.3) We developed a MATLAB toolbox that combines preprocessing, calculation of functional connectivity and statistical analysis for MDD and BD resting-state fMRI data.