State of the Art - Depression

Target Audience: Clinicians and researchers who are interested in getting an update on depression neuroimaging research-- where we've been, where we are and where we are heading. Objectives:1. Participants will appreciate the public health importance of neuroimaging research approaches that seek to advance current understanding of depression and its treatment.2. Participants will be able to discuss some of the seminal contributions that have been made in the past two decades of neuroimaging research, that have advanced our knowledge about the neural circuitry underlying depression and how that information may inform treatment.3. Participants will be able to articulate the next steps needed in the field of neuroimaging research to allow direct translation to patient care. Purpose: Major depressive disorder is a serious public health problem, representing a leading cause of worldwide disability, and a major contributor to suicide. While treatments exist to address this problem, they are not always efficacious, highlighting the need for more research to better understand the neural circuitry underlying depression and its treatment. Methods: In the past 2 decades, human neuroimaging research has made great strides in providing information about which neural circuits are implicated in depression. In this talk we will review some of the major contributions to this body of knowledge including research using structural neuroimaging, positron emission tomography, and functional magnetic resonance imaging. We will also discuss the smaller but emerging literature using these tools in the context of clinical trials to begin to understand predictors and mechanisms of treatment response in patients with depression. Results: The extant body of neuroimaging research has pointed to key neural circuits including fronto-limbic neural circuitry (1, 2) and the default mode network (3) in the pathophysiology of major depression. Notably, there has been some heterogeneity in the findings across studies. Recent efforts have addressed this issue, moving toward using neural information to identify depression biotypes (4). Predictive biomarkers of treatment response have been identified including activation of the anterior cingulate cortex (5, 6). Metabolism of the insula may be a differential biomarker of treatment response to standard antidepressant medications versus cognitive behavioral therapy (7). The field is farther behind in terms of identifying the neural changes that accompany treatment response, although some early studies have suggested changes in key networks implicated in depression (8–10). Discussion: While there have been great strides forward in understanding the neural circuitry underlying depression, much work still remains before this knowledge can be applied in the clinic. Heterogeneity in the findings across studies may reflect heterogeneity of MDD itself, where individuals that fall under the same diagnosis may have different neural circuitry signatures. Advanced methods that are designed to better understand these differences across subjects could provide the traction needed to develop personalized treatment approaches.

Acknowledgements

No acknowledgement found.

References

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