Presentation description

For decades, depression has earned the distinction of being the foremost contributor to disability on a global scale. However, the underlying pathology of this disorder remains largely unknown, leaving doctors to treat patients based on clinical manifestations, a treatment method that frequently falls short of satisfactory results. Neuroimaging techniques, such as magnetic resonance imaging (MRI) may help to untangle the complexities of structural abnormalities potentially related to psychological symptoms and behavioral deficits. In this study, we compared the variations in brain morphology between depressed subjects (n=23) and their healthy counterparts (n=16) using structural MRI. Prior to collecting scans, depression severity was measured with the Hamilton Depression Rating Scale and the Patient Health Questionnaire. T-1 weighted MRI scans were acquired and Fastsurfer software was utilized to extract cortical surface models and volumetric measurements for analysis. In comparison to healthy subjects, individuals with depression exhibited significantly diminished cortical thickness in three areas after multiple comparison correction: the rostral middle frontal gyrus (p = 0.038), the posterior cingulate cortex (p = 0.029), and the parahippocampal gyrus (p = 0.029). Several regions demonstrated reduced cortical thickness with age among depressed subjects, a pattern that was absent in healthy subjects. Furthermore, the severity of depression was correlated with the surface area of the right insula (p = 0.029, corrected for multiple comparisons); subjects who had lower insular surface areas tended to have more severe depressive symptoms. These outcomes demonstrate regional cortical deficits associated with depression and suggest that accelerated cortical aging may occur in depression. The results also suggest that the insular cortex may mediate depression severity. These findings highlight potential biomarkers and further elucidate roles of different brain regions in depressive illness.