The neural systems of emotion regulation and abnormalities in major depressive disorder.

Major depressive disorder (MDD) is a mental disorder characterized by aberrant emotion regulation. The capacity for emotion regulation stems from diverse neural circuits including higher level cognitive structures involved in processing contextual information, and lower level limbic structures involved in triggering emotional expression. Cognitive theories of depression posit that the MDD-specific abnormalities in emotional control derive itself from dysfunctional cognitive processes including biased attention, rumination, and altered information processing and memory. The main objectives of the current narrative review are to summarize the major neural systems involved in emotion regulation in humans, and to describe how these systems are dysregulated in MDD. The findings will be briefly discussed in the context of a conceptual framework of depression (i.e., Beck's cognitive model of depression), and neural targets of conventional treatments for depression will also be discussed. MDD exemplifies the critical importance of appropriate emotion regulation to human health and wellbeing, and demonstrates the personal and social impact of emotion dysregulation.