Self-referential processing in unipolar depression: Distinct roles of subregions of the medial prefrontal cortex

Self-concept is used to explain emotional disturbance or other behavioural and psychological problems associated with depression. Self-referential processing generally reflects self-concept in different domains. Cortical midline structures, such as the medial prefrontal cortex (MPFC), are critical for self-referential processing both in healthy controls and depressive patients. However, the role of subregions of the MPFC in self-referential processing in depression remains uncertain. In this study, we aimed to explore the neural basis of self-referential processing in depressive patients and the activation-deactivation patterns of subregions of the MPFC. Nineteen depressive patients and 21 controls completed the classic self-referential task with two different judgement conditions: self-referential processing and semantic processing. In the self-referential condition, with analysis of the two sample t-test unipolar patients showed significantly higher activation of the central MPFC and significantly lower activation of the dorsal MPFC, relative to controls. The results substantially suggested that the different activation of the MPFC may be selectively involved in self-referential processing in depressive patients, potentially indicating abnormal engagement of cognitive control and emotion regulation in this group.