Neural Links Between OCD and Anorexia

Individuals with anorexia nervosa (AN) have long been observed to demonstrate symptoms in common with obsessive-compulsive disorder (OCD), in particular, an obsessive fear of normal weight leading to dangerous food restriction, as well as many compulsive rituals about food. Both AN and OCD are seriously handicapping and often resistant to conventional therapies. Given that the two conditions often co-occur and are associated with still unknown genetic risk factors, the aim of this project is to identify their shared and distinct patterns of brain activity. The investigators propose to use functional magnetic resonance imaging to compare brain response among adolescents with AN, OCD, and age-matched healthy individuals. Specifically, this study will investigate function of distinct brain circuits related to core aspects of these related disorders. The investigators use three tasks related to set shifting, global vs. local processing, and reward. Based on evidence of deficits in cognitive flexibility and ability to change behavior, the investigators hypothesize that adolescents with AN and with OCD will show hypoactivity of frontostriatal circuitry during cognitive tasks, and adolescents with AN will show hyperactivity in limbic regions in a reward task. This study is the first to directly compare brain activation patterns using functional neuroimaging in AN and OCD. The goal is to determine how abnormal brain activity relates to symptom formation, what accounts for shared characteristics amongst these disorders, and whether deficits in specific circuitry underlie their unique defining features. The study of shared and unique elements of functional brain circuitry reflects a new, emerging approach to the classification of psychiatric illness, one based on identifying unique combinations of biological risk factors that link related conditions. This approach is widely believed to be a critical step forward in developing more brain-relevant targeted strategies for preventative interventions.