Neurobiological Model of Avoidant/Restrictive Food Intake Disorder

Abstract Little is known about the neurobiology of avoidant/restrictive food intake disorder, which was first added to the psychiatric nomenclature in 2013. Emerging evidence provides preliminary support for the three-dimensional neurobiological model of disorder, which posits that distinct constructs from the National Institute of Mental Health’s Research Domain Criteria underlie each of the three clinical phenotypes. First, there is emerging support that hyperactivation in Negative Valence Systems (particularly acute threat/fear) is associated with the ARFID-fear of aversive consequences phenotype. Second, there is increasing support that hypoactivation in Arousal and Regulatory Systems (particularly low homeostatic appetite) is associated with the ARFID-lack of interest phenotype. Third, there is mixed evidence about whether heightened sensitivity in Cognitive Systems (particularly sensory perception) is associated with the ARFID-sensory sensitivity phenotype. Although alternative theories of avoidant/restrictive food intake disorder neurobiology are also being investigated, the three-dimensional model has potential implications for etiology, maintenance, and treatment of this common and impairing disorder.