Neuroendocrine Mechanisms in Major Depressive Disorder: A Resting-State fMRI Study on ACTH-Related Brain Network Changes

Motivation: Major depressive disorder (MDD) patients often show varying levels of adrenocorticotropic hormone (ACTH), suggesting distinct neurobiological mechanisms. Goal(s): This study aimed to investigate resting-state brain connectivity in MDD patients with different ACTH levels. Approach: We analyzed functional connectivity from fMRI scans of 49 MDD patients and 21 healthy controls, stratifying participants based on ACTH levels. Results: Higher ACTH MDD patients displayed decreased global connectivity indicators and extensive connectivity changes compared to normal-ACTH patients, indicating distinct topological patterns related to HPA axis functionality. Impact: These findings suggest that MDD patients with varying ACTH levels exhibit unique brain network alterations, potentially informing neurobiological mechanisms and treatment strategies for hormone-related depression.