Anorexia nervosa (AN) and bulimia nervosa (BN) are two primary subtypes of eating disorders (ED), often presenting with overlapping clinical features that complicate diagnosis. Despite shared symptoms, the underlying neural mechanisms of two subtypes remain incompletely understood. Delineating both shared and unique neural alterations may support biomarker discovery and inform targeted interventions. We recruited 28 patients with AN, 26 with BN, and 31 matched healthy controls (HC), aged from 14 to 40 years old. Resting-state functional magnetic resonance image (Rs-fMRI) data were acquired to investigate alterations in spontaneous brain activity. Four voxel-wise metrics were analyzed: amplitude of low-frequency fluctuation (ALFF), fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), and degree centrality (DC). Symptom severity was assessed using the Eating Disorder Examination-Questionnaire (EDEQ), which includes four subscales: Eating concern (EDEQE), Shape concern (EDEQS), Weight concern (EDEQW), and Restraint (EDEQR). Pearson correlation analysis was used to examine associations between altered imaging metrics and clinical variables. Both AN and BN exhibited convergent alterations, including reduced activity in the bilateral middle frontal gyrus (MFG), insular cortex (INS), superior temporal gyrus (STG), and left parahippocampal gyrus (PHG), alongside increased activity in the bilateral striatum, middle occipital gyrus (MOG), and cerebellum. Disorder-specific alterations in AN included increased activity in the right striatum and right precuneus, increased DC in the right superior frontal gyrus (SFG), and decreased fALFF and DC in the left calcarine. In contrast, patients with BN exhibited elevated fALFF in the right precentral gyrus (PCGR) and increased DC in the right calcarine. Correlation analyses revealed negative association between the ReHo value of the MOGL and EDEQ, and positive associations between the DC value of the PCGR and EDEQ and EDEQE in patients with BN. Our findings revealed both shared and diagnosis-specific alterations in intrinsic brain activity within the cortico- striatal-limbic circuit, underscoring its role in the pathophysiology of ED. Anorexia nervosa (AN) and bulimia nervosa (BN) are the two primary subtypes of eating disorders (EDs) and often present with overlapping clinical features that complicate diagnosis. This study investigated the neural mechanisms underlying each subtype to identify both shared and disorder-specific neural alterations that may support biomarker discovery and inform targeted interventions. In this study, we examined brain activity in 28 patients with AN, 26 with BN, and 31 healthy controls. We used resting-state functional MRI to assess alterations in spontaneous brain activity, including neuronal activity, synchronization of local activity, and coordination across the whole brain. Our findings revealed both shared and diagnosis-specific alterations in intrinsic brain regions within cortico-striatal-limbic circuit, a network involved in cognitive processing, interoception, reward processing, and body image perception. We also found that some brain activity changes were related to symptom severity. These results improve our understanding of the biological mechanisms underlying eating disorders and may help guide the development of more personalized treatments in the future.
Teng et al. (Tue,) studied this question.