Brain structural and functional alterations in body dysmorphic disorder patients seeking cosmetic surgery: A resting-state multimodal MRI study.

BACKGROUND: Body dysmorphic disorder (BDD) is prevalent in cosmetic surgery populations, but its neurobiological mechanisms remain unclear. OBJECTIVE: To identify brain functional and structural alterations in BDD using multimodal MRI. METHODS: Twenty BDD patients and 20 healthy controls were recruited. After quality control, 16 per group were included in final analyses. ALFF, ReHo, functional connectivity (FC), VBM, and SBM analyses were performed, with correlations to clinical severity. RESULTS: BDD patients showed increased ALFF in right cerebellar lobule VIII and increased ReHo in left cerebellar lobule VIII. FC revealed enhanced mPFC-rectus gyrus connectivity and reduced PCC connectivity with left inferior parietal lobule and right midcingulate cortex. Exploratory structural analyses suggested increased gray matter in left middle occipital gyrus, decreased cerebellar/parietal volumes, altered white matter, cortical thickening in left pars triangularis, thinning in left inferior parietal lobule, and gyrification changes, but these did not survive multiple-comparison correction and require independent replication. Left inferior parietal cortical thickness positively correlated with BDD severity. CONCLUSIONS: BDD involves abnormalities in default mode, cerebellar-cortical, and visual processing networks, providing preliminary neurobiological insights into BDD. These group-level findings are exploratory and do not yet support individual-level applications. Given the modest sample size, replication in larger cohorts is required.