The Occipital-Fronto-Limbic Circuit of Body Dysmorphic Disorder: A Systematic Review and Meta-Analysis of Neuroimaging Studies.

Abstract

<h4>Background</h4>Body dysmorphic disorder (BDD) is a severe psychiatric disorder characterized by excessive preoccupation with perceived flaws in appearance. In this review, we aim to synthesize the latest findings on the neurobiology of BDD and propose an updated BDD neurocircuitry model.<h4>Methods</h4>A systematic search identified 38 peer-reviewed original articles, and the protocol was registered (CRD42024553665). Qualitative thematic analysis was conducted, and activation likelihood estimation (ALE) meta-analysis was performed to quantify brain activation patterns.<h4>Results</h4>Brain regions with significant morphometric divergence in patients with BDD were predominantly located in primary and secondary visual processing areas and temporal-limbic and frontal-striatal networks despite overall heterogeneous findings. The electroencephalography studies suggested early visual processing and attentional abnormalities. The ALE analysis revealed a general hyperactivation over the frontotemporal region and hypoactivation over parieto-occipital regions. Although BDD shared similar connectivity patterns in frontostriatal and arbitration networks with obsessive-compulsive disorder, it was further characterized by bottom-up and top-down interaction between the ventral visual stream and temporal-limbic network compared with anorexia nervosa. Neurotransmitters such as serotonin, dopamine, and oxytocin play a key role in the pathophysiology of BDD, suggesting a complex interplay of neural circuits and neurotransmitters underlying the disorder.<h4>Conclusions</h4>This comprehensive review of up-to-date neurobiological studies of individuals with BDD reveals differences in brain structure and functionality compared with control participants. The proposed neurocircuitry model expands on the previous understanding of BDD neurobiology and elucidates the interconnection between the visual processing, temporal-limbic, and frontostriatal networks and their clinical implications. This review provides theoretical support for future neuromodulation target identification.