Neuroimaging Insights into Depressive Disorders: Structural and Functional Brain Changes

• DOI: https://doi.org/10.22533/at.ed.1594542414069

• Palavras-chave: Depression; Neuroimaging; Functional Connectivity; Brain Structure; Treatment Response.

• Keywords: Depression; Neuroimaging; Functional Connectivity; Brain Structure; Treatment Response.

• Abstract: INTRODUCTION The introduction outlines the global burden of depressive disorders, emphasizing their impact on quality of life and the economy. It traces the historical development of neuroimaging in psychiatry, highlighting the importance of various imaging techniques such as MRI, fMRI, PET, and SPECT in uncovering the neurobiological underpinnings of depression. Key brain regions affected by depression, including the prefrontal cortex, hippocampus, and amygdala, are discussed, alongside neurotransmitter imbalances and default mode network (DMN) disruptions. The role of neuroinflammation, genetic influences, chronic stress, and gender differences in neuroimaging findings are also explored. OBJETIVE To review and synthesize current findings on structural brain abnormalities in depressive disorders. METHODS This is a narrative review which included studies in the MEDLINE – PubMed (National Library of Medicine, National Institutes of Health), COCHRANE, EMBASE and Google Scholar databases, using as descriptors: “Descriptors” AND “Neuroimaging Techniques” AND “Depressive Disorders” AND “Brain Structure and Function” AND “Treatment Response” AND “Neurobiological Markers” in the last years. RESULTS AND DISCUSSION This section delves into specific neuroimaging findings associated with depressive disorders. It discusses structural abnormalities such as reduced grey matter volume in critical regions like the prefrontal cortex and hippocampus, and functional connectivity changes within networks like the DMN and salience network. The discussion includes the impact of chronic stress and neuroinflammation on brain structure, the role of genetic factors, and the distinct neuroimaging profiles of treatment-resistant depression. Furthermore, the effects of therapeutic interventions, including antidepressants, psychotherapy, and neuromodulation techniques, on brain structure and function are analyzed. Gender differences, the relationship between cognitive impairment and neuroimaging findings, and the impact of sleep disturbances, substance abuse, and physical exercise on brain changes in depression are also covered. CONCLUSION The introduction outlines the global burden of depressive disorders, emphasizing their impact on quality of life and the economy. It traces the historical development of neuroimaging in psychiatry, highlighting the importance of various imaging techniques such as MRI, fMRI, PET, and SPECT in uncovering the neurobiological underpinnings of depression. Key brain regions affected by depression, including the prefrontal cortex, hippocampus, and amygdala, are discussed, alongside neurotransmitter imbalances and default mode network (DMN) disruptions. The role of neuroinflammation, genetic influences, chronic stress, and gender differences in neuroimaging findings are also explored.