Appetitive Conditioning in Anorexia Nervosa
Anorexia NervosaAnorexia nervosa (AN) is characterized by a reduced drive to pursue rewarding experiences and stimuli. Food consumption - which is almost universally experienced as pleasurable - is not described as rewarding by those with AN. This is thought to be underpinned by abnormalities around reward learning. However, the most fundamental question relating to reward in AN - whether those with AN may learn positive associations - remains unaddressed.
In this study, the investigators will identify the patterns of how those with AN acquire positive associations, how they diminish, and their relationships to physiology (heart rate and pupil responses) and brain activation. In assessing the robustness of this learning, the investigators will investigate the extent to which this association is reactivated after 24 hours, and the extent to which a memory prompt will help reinstate this previously learned positive association.
This project will allow for important advances in our understanding of the neurobiology of AN. The investigators will first identify if, and how, those with AN come to learn positive associations to cues, and secondly, the extent to which learned positive associations remain over time. Moreover, the investigators will use machine learning to ascertain whether reward learning can be predicted by physiological and neural biomarkers.
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Participation Requirements
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Sex:
FEMALE -
Eligible Ages:
12 to 22
Participation Criteria
Inclusion Criteria:
1. AN-Restricting (AN-R) Group
Inclusion criteria:
1. Females from any racial or ethnic background
2. Ages between 12 and 22 years
3. Meet DSM-5 criteria for AN - restricting subtype
4. Medically stable designated by their physician in the past month (having any of the following measurements taken by a physician or nurse within the past month preceding the telephone screen: (i) orthostasis: drop in systolic blood pressure \> 20 mm Hg or diastolic blood pressure \> 10 mm Hg, or an increase in heart rate (HR) \> 20 bpm upon standing for 3 minutes after lying down; (ii) resting HR \<45; or (iii) resting blood pressure of \<80 mm Hg systolic or \<50 mm Hg diastolic 99. Prospective participants who do not meet the medical instability criteria and otherwise pass the telephone screen, will be invited to proceed to the consent process. If they have not had these measurements done in the month prior, we will encourage them to visit their doctor or nurse to have these done and then to recontact us with the results ):
5. BP and pulse measured at the day of the scan by the investigators
* Heart rate ≥ 45 at rest
* Resting blood pressure of ≥80 mm Hg systolic and ≥50 mm Hg diastolic
* Lying and standing (after 3 min.) BP drop of ≤20 systolic and ≤10 diastolic and increase in HR ≤20 bpm
6. Not taking psychiatric medications or taking serotonin-reuptake inhibitor or serotonin-norepinephrine reuptake inhibitor medications at stable doses
2. History of AN-Restricting Group:
Inclusion criteria:
1. Females from any racial or ethnic background
2. Ages between 12 and 22 years
3. EDE-Q ≤ 2 (puts them within 1 standard deviation \[SD\] of community norms and lower than 1 SD from clinical norms for female AN-R)
4. History of AN - meeting full criteria, diagnosed by a licensed clinician
5. Not taking psychiatric medications or taking serotonin-reuptake inhibitor or serotonin-norepinephrine reuptake inhibitor medications at stable doses
3. Healthy controls:
Inclusion criteria:
1. Healthy females from any racial or ethnic background
2. Ages 12-22 years
Exclusion Criteria:
* AN-R and History of AN-R groups:
1. Antipsychotic medications
2. Change in dose of psychotropic medication over the previous 4 weeks
3. Current psychotic disorder
Healthy controls:
1. Any current Axis I disorder
2. Eating Disorder Examination Questionnaire score greater than established community norms (\>2)
3. Met criteria for AN (in the past or present)
All:
1. Neurological disorder
2. Infants or children of their own
3. Pregnancy
4. Current risk of suicide with a plan and intent
5. Ferromagnetic metal implantations or devices (electronic implants or devices, infusion pumps, aneurysm clips, metal fragments or foreign bodies, metal prostheses, joints, rods or plates)
Study Location
Centre for Addiction and Mental Health
Centre for Addiction and Mental HealthToronto, Ontario
Canada
Contact Study Team
- Study Sponsored By
- Centre for Addiction and Mental Health
- Participants Required
- More Information
- Study ID:
NCT05531604