Bulimia Nervosa
Conditions
Brief summary
An impaired ability to exert control has been implicated in bulimia nervosa (BN), but this impairment may not represent a stable trait or be the most effective focus for treatment. This project aims to understand how predictions and value-based decisions about control may be abnormally influenced by eating in individuals with BN, thereby maintaining cycles of binge eating, purging, and restriction.
Detailed description
The overarching goal of this project is to test a neurocomputational model of BN that incorporates learning and decision-making components of control. The study combines functional magnetic resonance imaging (fMRI), computational modeling, and real-time mobile assessments to examine the influences of acute fasting and eating on brain function and associated control-related updating and effort-valuation processes in BN. More specifically, the study has the following main objectives: 1) To determine the influence of eating on control-related prediction updating in BN.; 2) To determine the influence of eating on control-related cognitive effort valuation in BN; 3) To use state-specific neural activation to predict BN symptoms.
Interventions
OTHERFasting state
16 hours of fasting
OTHERFed state
Fed a standardized meal
OTHERMagnetic Resonance Imaging
Neuroimaging with computational modeling
Sponsors
Icahn School of Medicine at Mount Sinai
National Institute of Mental Health (NIMH)
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
SINGLE (Outcomes Assessor)
Intervention model description
Two participant groups (one with and one without bulimia nervosa) will be scanned using MRI after they have fasted and after they have consumed a standardized meal. The order of these two scans will be counterbalanced across groups.
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Female * Aged 18 to 45 years * Current BMI greater than or equal to 18.5kg/m2 but under 30kg/m2 * Right-handed * English-speaking Additional Inclusion Criteria for Women with Bulimia Nervosa: * Meet DSM-5 criteria for bulimia nervosa
Exclusion criteria
* Medical instability * Ongoing medical treatment, medical condition, or psychiatric disorder that may interfere with study variables or participation * Shift work * Pregnancy, planned pregnancy, or lactation during the study period * Allergy to any of the ingredients in or unwillingness to consume the standardized meal or unwillingness to drink water during the fasting period * Any contraindication for fMRI
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Frontostriatal Activation Associated with Prediction Errors on the Stop Signal Task | 1-2.5 hours after a 16-hour fast (fasted state) | Blood oxygen level dependent (BOLD) signal in frontostriatal brain circuitry associated with inhibitory control prediction errors |
| Frontostriatal Activation Encoding the Subjective Value of Cognitive Effort on the Cognitive-Effort Discounting Task | 1-2.5 hours after a 16-hour fast (fasted state) | Blood oxygen level dependent (BOLD) signal in frontostriatal brain circuitry associated with the subjective value of expending cognitive effort on control |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Percent correct responses to stop trials and the trial-by-trial association | 1-2.5 hours after a 16-hour fast (fasted state) | Behavioral performance on the stop signal task, as measured by percent correct responses to stop trials and the trial-by-trial association between the predicted likelihood that upcoming inhibition is needed (P(stop)) from a Bayesian ideal observer model and accuracy |
| Cognitive Effort Discounting Task Behavioral Performance | 1-2.5 hours after a 16-hour fast (fasted state) | The subjective value of cognitive effort estimated for each N-back load level and cost- and benefit-modulated drift rate parameters from a drift- diffusion model applied to behavioral performance data |
| Binge-eating Severity | Baseline and 6-month follow-up | The frequency of binge-eating episodes as assessed by the Eating Disorder Examination (EDE) and Ecological Momentary Assessment (EMA). Binge-eating frequency has a minimum limit of 0 and no maximum limit. A higher score indicates a greater severity. |
| Compensatory Behavior Severity | Baseline and 6-month follow-up | The frequency of compensatory behaviors as assessed by the EDE and EMA. This frequency has a minimum limit of 0 and no maximum limit. A higher score indicates a greater severity. |
| Dietary Restriction Severity | Baseline and 6-month follow-up | The frequency of fasting episodes as assessed by the EDE avoidance of eating item (minimum limit = 0, maximum limit = 6); the severity of dietary restriction as assessed by the Eating Pathology Symptoms Inventory (EPSI) - restricting subscale (minimum limit=0; maximum limit=24), and the frequency of restrictive eating behaviors as assessed by EMA (minimum limit=0; no maximum limit). On all measures, a higher score indicates a greater severity. |
Countries
United States
Contacts
CONTACTRiley Macks, B.A.
CONTACTRiley Macks
PRINCIPAL_INVESTIGATORLaura A Berner, Ph.D.
Mount Sinai Icahn School of Medicine
Outcome results
None listed