Altered functional connectivity in binge eating disorder and bulimia nervosa: A resting‐state fMRI study

Abstract

Introduction The etiology of bulimic‐type eating (BTE) disorders such as binge eating disorder (BED) and bulimia nervosa (BN) is still largely unknown. Brain networks subserving the processing of rewards, emotions, and cognitive control seem to play a crucial role in the development and maintenance of eating disorders. Therefore, further investigations into the neurobiological underpinnings are needed to discern abnormal connectivity patterns in BTE disorders. Methods The present study aimed to investigate functional as well as seed‐based connectivity within well‐defined brain networks. Twenty‐seven individuals with BED, 29 individuals with BN, 28 overweight, and 30 normal‐weight control participants matched by age, gender, and education underwent resting‐state functional magnetic resonance imaging. Functional connectivity was assessed by spatial group independent component analysis and a seed‐based correlation approach by examining the default mode network (DMN), salience network (SN), and executive network (EN). Results Group comparisons revealed that BTE disorder patients exhibit aberrant functional connectivity in the dorsal anterior cingulate cortex (dACC) within the SN, as well as in the medial prefrontal cortex within the DMN. Furthermore, BED and BN groups differed from each other in functional connectivity within each network. Seed‐based correlational analysis revealed stronger synchronous dACC‐retrosplenial cortex activity in the BN group. Conclusion Our findings demonstrate abnormalities in brain networks involved in salience attribution, self‐referential processing, and cognitive control in bulimic‐type eating disorders. Together with our observation of functional connectivity differences between BED and BN, this study offers a differentiated account of both similarities and differences regarding brain connectivity in BED and BN.

A review of the relationship between eating behavior, obesity and functional brain network organization

“…To date, only 11 studies have examined the relationship between functional network organization and clinical eating phenotypes most typically associated with obesity. Of these, only two studies included individuals with a BMI in the overweight or obese range ( Geliebter et al , 2016 ; Stopyra et al , 2019 ). Further, very little is known about functional network organization in BED, the eating disorder most frequently co-occurring with obesity.…”

“…This suggests that regions involved in body awareness and sensation might be more integrated in BN, which may be associated with body image distortions and enhanced responsiveness to food cues. Similarly, BED has also been linked to enhanced resting connectivity between regions of somatosensory cortex ( Stopyra et al, 2019 ). Moreover, the strength of connectivity was positively correlated with the frequency of binge episodes ( Stopyra et al, 2019 ), providing evidence that stronger coupling of these regions represents a neural signature of binge eating.…”

Volumetric and connectivity changes in brain networks associated with reward sensitivity, cognitive control, and negative affect in binge eating disorder and bulimia nervosa

“…On the other hand, BED showed higher connectivity values in the right cerebellum and right lingual gyrus compared with HC. When comparing BN and BED directly, BED showed a higher connectivity in posterior dorsal cingulate cortex, but lower connectivity in the middle frontal gyrus and angular gyrus (Stopyra et al, 2019). To summarize, BN and BED showed less connectivity in the salience network (aDCC, dACC), higher connectivity in the default mode network, but only in BN (dorsal mPFC, lateral ventral mPFC), and both higher and lower connectivity in the executive network (middle frontal gyrus, angular gyrus, inferior parietal cortex).…”

“…Functional connectivity changes (see Table 1 functional connectivity) largely overlap with the structural connectivity changes discussed above (section 2.2). A large study determining differences in functional connectivity in BED and BN compared with HC (Stopyra et al, 2019) showed lower connectivity in the anterior part of the dorsal cingulate cortex (aDCC), the dorsal part of the anterior cingulate cortex (dACC), and inferior parietal cortex in BED and BN. BED showed lower connectivity within the dorsal medial prefrontal cortex, whilst it was higher in BN compared with HC.…”

Characterizing impulsivity and resting‐state functional connectivity in normal‐weight binge eaters

“…This approach aims to identify taskindependent and more fundamental functional patterns underlying different states and/or disorders (Fox & Greicius, 2010). RsfMRI has been adopted to describe functional connectivity in relation to eating and weight disorders (García-García et al, 2015;Stopyra et al, 2019), and preliminary evidence converges in identifying altered functional connectivity patterns in regions mainly implicated in impulsivity-related aspects (such as, prefrontal, subcortical and parietal regions) in overeating conditions (García-García et al, 2015;Moreno-Lopez, Contreras-Rodriguez, Soriano-Mas, Stamatakis, & Verdejo-Garcia, 2016;Park, Seo, & Park, 2016). For example, functional connectivity changes within the frontoparietal circuit have been linked to disinhibited eating behavior (as assessed by Three Factor Eating Questionnaire, TFEQ; Stunkard & Messick, 1985) and body mass index (BMI) in normal-and overweight individuals (Park et al, 2016).…”