Functional connectivity between extrastriate body area and default-mode network predicts depersonalization symptoms in major depression: Findings from an a priori specified multi-network comparison

Abstract Background Depersonalization/derealisation disorder (DPD) is a dissociative disorder characterized by feelings of unreality and detachment from the self and surroundings. DPD is classified as a primary disorder, but depersonalization symptoms are frequently observed in mood and anxiety disorders. In the context of major depressive disorder (MDD), depersonalization symptoms are associated with greater depressive severity as indexed by treatment resistance, inpatient visits, and duration of depressive episodes. In the current investigation, we test four network-based, neural-functional hypotheses of depersonalization in MDD. These hypotheses are framed in terms of functional relations between: 1) extrastriate body area (EBA) and default mode network (DMN); 2) hippocampus and DMN; 3) medial prefrontal cortex and ventral striatum; and 4) posterior and anterior insular cortex. Methods We conducted functional magnetic resonance imaging during resting state on 28 female patients diagnosed with MDD and 27 never-disordered controls. Functional connectivity between seed and target regions as specified by our network-level hypotheses was computed and correlated with scores on the Cambridge Depersonalization Scale. We used a conservative, unbiased bootstrapping procedure to test the significance of neural-behavioral correlations observed under each of the four models tested. Results Of the four neural-functional models of depersonalization symptoms tested, only the one proposing that reduced connectivity between the EBA and DMN predicts higher levels of depersonalization symptoms in MDD was confirmed. Conclusion Our results indicate that DPD symptoms in depressed patients are related to reduced functional connectivity between brain regions that are proposed to support processing of body-related (EBA) and autobiographical (DMN) information.