Understanding reward learning in anorexia nervosa

Appetitive Conditioning in Anorexia Nervosa: Neural, Physiological, and Behavioral Mechanisms

This study is trying to see how people with anorexia nervosa learn to connect positive feelings with food and social interactions, and it includes participants who are underweight, weight-restored, and healthy to help understand these patterns better.

Quick facts

• Study type: Observational
• Enrollment: 90 (estimated)
• Ages: 12 Years to 22 Years
• Sex: Female
• Sponsor: Centre for Addiction and Mental Health (Academic / other)
• Locations: 1 site (Toronto, Ontario)
• Trial ID: NCT05531604 on ClinicalTrials.gov

What this trial studies

This study investigates how individuals with anorexia nervosa (AN) learn to associate positive experiences with rewards, particularly focusing on food consumption and social interactions. It aims to identify patterns of reward learning and how these associations may diminish over time, as well as their physiological and neural correlates. The study will enroll 90 participants, including underweight individuals with AN, weight-restored individuals, and healthy controls, to perform a reward conditioning task using social rewards. The findings could provide insights into the underlying mechanisms of reward processing in AN and inform future treatment approaches.

Who should consider this trial

Good fit: Ideal candidates include females aged 12-22 who meet the DSM-5 criteria for the restricting subtype of anorexia nervosa and are medically stable.

Not a fit: Patients who do not meet the criteria for anorexia nervosa or those who are not medically stable may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to new therapeutic strategies that enhance reward learning in patients with anorexia nervosa.

How similar studies have performed: While studies have explored reward processing in anorexia nervosa, this specific approach using appetitive conditioning is relatively novel.

Eligibility 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)

Where this trial is running

Toronto, Ontario

• Centre for Addiction and Mental Health — Toronto, Ontario, Canada (Recruiting)

Study contacts

• Principal investigator: Jamie D Feusner, M.D. — Centre for Addiction and Mental Health
• Study coordinator: Research Analyst

Conditions Anorexia Nervosa; appetitive conditioning; pavlovian conditioning; reward learning; reinforcement learning; associative learning; extinction