Self-Control in Bulimia Nervosa

Study Overview
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Brief Summary
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This study examines the influence of acute fasting and eating on self-control in adult females with and without bulimia nervosa (BN). Specifically, the study team is investigating whether differences in behavior and brain activation in response to computer tasks after fasting and after eating a meal could help to explain the symptoms of bulimia nervosa. Data will be collected using questionnaires and a technology called magnetic resonance imaging (MRI).

Detailed Description
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Treatment-resistant binge eating and purging may be perpetuated by self-control deficits linked to reduced activation in frontostriatal circuits. To date, however, neurocognitive studies of BN have not assessed the dynamic computational processes underlying inhibition or considered the fact that individuals with BN oscillate between two extremes-under-controlled and over-controlled intake. The proposed study combines neuroimaging with computational modeling to investigate the influences of acute fasting and eating (i.e., metabolic states) on how the brains of women with bulimia nervosa (BN) adaptively prepare for and exert inhibitory control. More specifically, the study has the following main objectives: 1) To determine whether eating and fasting affect adaptive inhibitory control and related frontostriatal activation abnormally in BN; 2) To identify associations of BN severity with state-specific frontostriatal activation and behavior.

Official Title
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The Influences of Eating and Fasting on Inhibitory Control in Bulimia Nervosa: A Computational Neuroimaging Study

Conditions
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Bulimia Nervosa

Intervention / Treatment
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* Other: fasting state
* Other: fed state
* Other: magnetic resonance imaging


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Female Aged 18 to 35 years Currently between 85 and 130% of the expected weight for height 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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional 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.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Participants with Bulimia Nervosa<br>Participants are randomly assigned (in even numbers across the two groups) to scan order: A. These participants are first scanned after 16 hours of fasting on one day, and are next scanned after a standardized meal on a second day. B. These participants are first scanned after a standardized meal on one day, and are next scanned after 16 hours of fasting on a second day. | Other: fasting state<br>* 16 hours of fasting<br>Other: fed state<br>* fed a standardized meal<br>Other: magnetic resonance imaging<br>* neuroimaging with computational modeling<br>* Other names: MRI;|
| Other: Participants without Bulimia Nervosa<br>Participants are randomly assigned (in even numbers across the two groups) to scan order: A. These participants are first scanned after 16 hours of fasting on one day, and are next scanned after a standardized meal on a second day. B. These participants are first scanned after a standardized meal on one day, and are next scanned after 16 hours of fasting on a second day. | Other: fasting state<br>* 16 hours of fasting<br>Other: fed state<br>* fed a standardized meal<br>Other: magnetic resonance imaging<br>* neuroimaging with computational modeling<br>* Other names: MRI;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| P(stop) at fasting state | Frontostriatal activation associated with the predicted likelihood that upcoming inhibition is needed (P(stop)) | at 16 hours after fast | 
| Prediction errors at fasting state | Frontostriatal activation associated with: inhibitory control prediction errors (signed and unsigned) | at 16 hours after fast | 
| Successful inhibition at fasting state | Frontostriatal activation associated with successful inhibition | at 16 hours after fast | 
| P(stop) at fed state | Frontostriatal activation associated with the predicted likelihood that upcoming inhibition is needed (P(stop)) | at 30 minutes after a standardized meal | 
| Prediction errors at fed state | Frontostriatal activation associated with inhibitory control prediction errors (signed and unsigned) | at 30 minutes after a standardized meal | 
| Successful inhibition at fed state | Frontostriatal activation associated with successful inhibition | at 30 minutes after a standardized meal | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Stop Signal Reaction Time (SSRT) at fasting state | Behavioral performance on the stop signal task, as measured by stop signal reaction time | at 16 hours after fast | 
| Stop Signal Reaction Time (SSRT) at fed state | Behavioral performance on the stop signal task, as measured by stop signal reaction time | at 30 minutes after a standardized meal | 
| Stop Signal Task Performance at fasting state | Percent correct responses to stop trial on Stop Signal Task Performance | at 16 hours after fast | 
| Stop Signal Task Performance at fed state | Percent correct responses to stop trial on Stop Signal Task Performance | at 30 minutes after a standardized meal | 
| Frequency of Eating Disorder Symptom Episodes | The frequency of binge eating episodes, self-induced vomiting episodes, and fasting episodes as assessed by the Eating Disorder Examination (EDE). Frequency of episodes assessed with no minimum or maximum limit. | Baseline (At study screening) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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bulimia nervosa, binge eating, purging, fasting, eating disorder, control