Neuroimaging aspects of interception in mood disorders: A systematic review.

Introduction: Mood disorders often involve attenuated interoception, which impairs the accurate perception and interpretation of internal bodily signals. Functional magnetic resonance imaging has been used to explore the neurobiology of interoception in vivo while participants are performing interoceptive tasks.

Aim: The aim of this review is to present the progress in neuroimaging studies of interoception in mood disorders.

Methods: We performed a systematic search in Pubmed, Scopus and Web of Science with the terms "interoception", "depression", "bipolar disorder", "mood disorders", "neuroimaging" and derivative terms.

Results: 461 records have been identified in the 3 databases, 34 records were assessed for eligibility and finally 17 reports were selected. The main findings were: disrupted cardioception in Major Depressive Disorder (MDD) which was related to reduced insular activity; altered visceroception in major depression has been linked to hypoactivation in the dorsal mid-insula; reduced nociception was reflected by hypoactivation in the insula in both MDD and Bipolar Disorder, and altered insular activity has been linked to maladaptive eating behavior.

Discussion & Conclusion: The current review demonstrated that neuroimaging studies focusing on interoceptive tasks in mood disorders are limited in both number and sample size. This is notably relevant to bipolar disorder where only one publication was found. Nevertheless, we were able to outline the findings on four separate aspects of interoception - cardioception, visceroception, nociception and appetite all of which are pointing to the insula as core dysfunctional region. Further research is needed to draw more conclusive insights and improve our understanding of interoception in mood disorders.