Increased Functional Connectivity Between Ventral Attention and Default Mode Networks in Adolescents With Bulimia Nervosa.

Objective: Bulimia nervosa (BN) is characterized by excessive attention to self and specifically to body shape and weight, but the ventral attention (VAN) and default mode (DMN) networks that support attentional and self-referential processes are understudied in BN. This study assessed whether altered functional connectivity within and between these networks contributes to such excessive concerns in adolescents with BN early the course of the disorder.

Method: Resting-state functional magnetic resonance images were acquired from 33 adolescents with BN and 37 healthy control adolescents (12-21 years) group matched by age and body mass index. Region-of-interest analyses were performed to examine group differences in functional connectivity within and between the VAN and DMN. In addition associations of VAN-DMN connectivity with BN symptoms, body shape/weight concerns, and sustained attention were explored using the Continuous Performance Test (CPT).

Results: Compared with control adolescents, those with BN showed significantly increased positive connectivity between the right ventral supramarginal gyrus and all DMN regions and between the right ventrolateral prefrontal cortex and the left lateral parietal cortex. Within-network connectivity did not differ between groups. VAN-DMN connectivity was associated with BN severity and body shape/weight concerns in the BN group. No significant group-by-CPT interactions on VAN-DMN connectivity were detected.

Conclusion: Increased positive VAN-DMN connectivity in adolescents with BN could reflect abnormal engagement of VAN-mediated attentional processes at rest, perhaps related to their excessive attention to self-referential thoughts about body shape/weight. Future studies should further investigate these circuits as targets for the development of early interventions aimed at decreasing excessive body shape/weight concerns.