Distinct functional connectivity of anterior cingulate cortex subregional networks in first-episode and recurrent major depressive disorder

Motivation: The fine-grained anterior cingulate cortex (ACC) subregional functional connectivity alterations in first-episode and recurrent major depressive disorder (MDD) remained unclear. Goal(s): To obtain optimal functional ACC subdivisions and explore alterations in intrinsic functional connectivity of ACC subregional networks in first-episode and recurrent MDD. Approach: We utilized a data-driven connectivity-based parcellation to obtain optimal ACC subdivisions, calculated ACC subregional functional connectivity, and compared among first-episode, recurrent MDD patients and healthy controls. Results: Ventral and dorsal ACC per hemisphere were identified as optimal parcellation. The ACC subregional connectivity was reduced in all MDD patients, while dorsal ACC connectivity was significantly reduced only in recurrent patients. Impact: Our discovery of impaired functional architectures of ACC subdivisions in MDD, with a more prominent disrupted connectivity of dorsal ACC in relapsed patients, emphasize a potential role of ACC subregional connectivity in distinguishing MDD at different episodes and predicting relapse.