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.