Functional connectivity and treatment response in obesity and eating disorders: Current evidence and empirical data.

Alterations in large-scale brain networks have been reported in obesity (OB) and eating disorders (ED), but their relevance to treatment outcomes remains unclear. We reviewed evidence on neurobiological predictors of treatment outcome in ED and OB and present preliminary empirical analyses exploring baseline rsFC differences between individuals with anorexia nervosa (AN), obesity with comorbid ED (OB + ED), and obesity without ED (OB - ED) and healthy controls (HC), and examining whether these connectivity differences are associated with treatment outcome in the clinical groups. A total of 98 women (AN = 27, OB + ED = 25, OB - ED = 21, HC = 25) underwent resting-state functional magnetic resonance imaging (rs-fMRI). rsFC networks were subsequently identified using probabilistic independent component analysis (ICA), and their associations with treatment outcomes were examined within each clinical group. Both OB groups showed reduced rsFC relative to HC within a thalamic-basal ganglia network, specifically in a cluster located in the left inferior occipital cortex encompassing extrastriate visual regions. Baseline connectivity in this occipital cluster showed a positive, although non-significant, association with treatment outcome in the OB - ED group, whereas no significant associations were observed in AN or OB + ED. Given the non-significant nature of this exploratory association, the observed relationship should be considered hypothesis-generating and requires confirmation in adequately powered samples. Further work is needed to clarify the role of sensory-integrative networks in treatment response across extreme weight conditions.