Common and Distinct Phenotypes of Body Dysmorphic Disorder and Anorexia Nervosa

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DESCRIPTION (provided by applicant): The purpose of this study is to characterize shared and unique brain circuits associated with Body Dysmorphic Disorder (BDD) and Anorexia Nervosa (AN) using a set of functional neuroimaging experiments. BDD and anorexia nervosa AN are severe and disabling psychiatric disorders that share many clinical features such as distorted body image and overvaluation of appearance for self-worth, yet they are currently classified in separate diagnostic categories. Despite their significant morbidity and mortality, very little research has been conducted to compare and contrast these disorders in order to understand the underlying neurobiology of shared and unique clinical phenotypes. An important shared clinical phenotype in BDD and AN is perceptual distortion of appearance, which may contribute to distorted body image. There is early evidence of similar, common phenotypes of disturbances in visual perception and visuospatial processing in BDD and AN, as evidenced clinically and from neuropsychological testing. However, little is known of the underlying neurobiological processes that mediate these. A preliminary functional magnetic resonance imaging (fMRI) study in adults with BDD demonstrated abnormal activation in left hemisphere regions responsible for high-detail processing when viewing others' faces. A more recent study in BDD demonstrated no abnormalities of primary emotional processing regions when viewing own-faces. AN, on the other hand, is often characterized by early, childhood-onset anxiety in addition to extreme fears of weight gain. However, no study has specifically examined fear processing in AN nor compared it to BDD. The goal of the proposed study is to define the common and distinct and phenotypes of visual and emotional processing in BDD and AN that map onto specific brain systems. This study will enroll 25 subjects with BDD, 25 with weight-restored AN, and 25 healthy controls, ages 18-30. Functional magnetic resonance imaging (fMRI) will be used to identify key abnormalities in brain systems associated with visual and emotional processing. Based on previous fMRI research in BDD, and our pilot data and previous studies suggesting abnormalities of detail-processing in AN, this study will investigate visual processing of others' faces, bodies, and non-face objects (houses) using different types of visual images that convey high, low, or normal level of detail. To compare and contrast patterns of emotional processing, this study will use fearful face stimuli to understand common or distinct brain activity patterns associated with emotional reactivity, regulation, and habituation. . PUBLIC HEALTH RELEVANCE: This study will characterize brain circuitry associated with perceptual distortions and emotional processing in these severe and disabling disorders of body image to establish the neural basis for their shared and distinct clinical features. This will assist in refining classification schemes based on an understanding of underlying brain mechanisms and not merely surface symptoms and behaviors. It will also lay the foundation for future development of novel therapeutics such as perceptual retraining and emotion regulation techniques.