Incentive Processing and Learning in Anorexia Nervosa and Bulimia Nervosa

Incentive Processing and Learning in Anorexia Nervosa and Bulimia Nervosa

The purpose of this study is to investigate areas of the brain responsible for 'liking', 'wanting', and learning in adults with eating disorders using brain imaging techniques, computer tasks, a test meal, and self-report questionnaires and interviews. The investigators will study changes in brain activity using a procedure called functional magnetic resonance imaging (fMRI). This study will include 252 women with an eating disorder (63 AN-restricting type (AN-R), 63 AN-binge eating/purging type (AN-BP), 63 bulimia nervosa (BN)) and 63 healthy controls (HC) aged 18-39.

Aim 1: To examine neural differences in 'liking' and 'wanting' in ED relative to HC.

Aim 2: To examine differences in instrumental learning for reward and punishment in ED relative to HC.

Aim 3: To examine how 'liking' and 'wanting' drive instrumental learning in ED and predict clinical symptoms at baseline and 1 year later.

Exploratory Aim: To explore the associations of dopamine function, as measured by neuromelanin MRI (NM-MRI), with ED diagnosis and brain response to 'liking', 'wanting', and learning.

Inclusion Criteria:

Eating Disorder Group:

• Between the ages of 18 and 39 years old
• Meet DSM-V criteria for AN-R, AN-BP, or BN

Healthy Control Group:

• Between the ages of 18 and 39 years old
• Have maintained 85% to 120% ideal body weight since menarche

Exclusion Criteria:

All Groups:

• Psychotic illness/other mental illness requiring hospitalization
• Current dependence on drugs or alcohol defined by DSM IV criteria. Additionally, positive test results for drug use on the day of the scan, apart of marijuana, will result in cancelling or rescheduling the scan because acute use will impact MRI measures.
• Physical conditions (e.g. diabetes mellitus, pregnancy) known to influence eating or weight
• Neurological disorder, neurodevelopmental disorder, or history of head injury with >30 min loss of consciousness
• Any contraindication to undergoing an MRI
• Primary obsessive compulsive disorder or primary major depressive disorder

Additional Exclusion Criteria for ED Group:

-If taking other psychotropic medication, any change in dosage in the 2 weeks before scanning

Additional Exclusion Criteria for Healthy Control Group:

• Meet criteria for the diagnosis of any psychiatric disorder currently
• Any history of binge eating or purging behaviors, including self-induced vomiting, laxative or diuretic misuse
• Use of any psychoactive or other medication known to affect mood or concentration in the last 3 months