Abnormal regional spontaneous brain activity in major depressive disorder with obesity comorbidity: A resting-state functional magnetic resonance imaging study.

BACKGROUND: Major depressive disorder (MDD) and obesity (OB) are bidirectionally comorbid conditions with common neurobiological underpinnings. However, the neurocognitive mechanisms of their comorbidity remain poorly understood. AIM: To examine regional abnormalities in spontaneous brain activity among patients with MDD-OB comorbidity. METHODS: This study adopted a regional homogeneity (ReHo) analysis of resting-state functional magnetic resonance imaging. The study included 149 hospital patients divided into four groups: Patients experiencing their first episode of drug-naive MDD with OB, patients with MDD without OB, and age- and sex-matched healthy individuals with and without OB. Whole-brain ReHo analysis was conducted using SPM12 software and RESTplus toolkits, with group comparisons via ANOVA and post-hoc tests. Correlations between ReHo values and behavioral measures were examined. RESULTS: ANOVA revealed significant whole-brain ReHo differences among the four groups in four key regions: The left middle temporal gyrus (MTG.L), right cuneus, left precuneus, and left thalamus. Post-hoc analyses confirmed pairwise differences between all groups across these regions (P < 0.05). OB was associated with ReHo alterations in the MTG.L, right cuneus, and left thalamus, whereas abnormalities in the precuneus suggested synergistic pathological mechanisms between MDD and OB. Statistically significant correlations were found between the drive and fun-seeking dimensions of the behavioral activation system, as well as behavioral inhibition and the corresponding ReHo values. CONCLUSION: Our findings provide novel evidence for the neuroadaptive mechanisms underlying the MDD-OB comorbidity. Further validation could lead to personalized interventions targeting MTG.L hyperactivity and targeting healthy food cues.