An observational study in Anorexia Nervosa, sponsored by Centre for Addiction and Mental Health. Active, not recruiting at 1 site in Canada. Open to female participants aged 12 Years to 22 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-03-27.
Sponsored by Centre for Addiction and Mental Health · Observational
Anorexia 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.
Individuals with anorexia nervosa (AN) suffer from anxiety, reduced pleasure from normally rewarding situations (anhedonia), and disturbed body image. However, restriction of calories from their morbid fear of weight gain, resulting in starvation, typically brings them to attention and has been the primary focus of most treatments and many research studies. Yet, treatments have largely been inadequate, with remission rates less than 25%. Anhedonia and disturbances in reward may be important targets of new treatment approaches. Those with AN report little pleasure in food consumption, social domains, and pursuit of novelty and fun. Neuroimaging studies demonstrate disturbances in reward circuits in response to food- and body-related stimuli and monetary rewards, but results are inconsistent. This may be due to confounding effects of anxiety triggered by symptom-related stimuli. Further, a fundamental process of the overall reward response that has not been studied in AN is reward learning - how one's brain learns to associate stimuli with the experience of reward ("appetitive Pavlovian conditioning"). To investigate this, the investigators will enroll 30 underweight individuals with AN, 30 with weight-restored AN, and 30 healthy controls ages 12-22 to perform a reward conditioning paradigm. The investigators will use infant laughter, a social reward with robust effects that is unlikely to be confounded by other co-occurring symptoms. To understand associated neural activity and physiological responses, the investigators will perform conditioning and examine reinstatement 24-hours later, while obtaining functional magnetic resonance imaging, heart rate deceleration, and pupil dilation data, in addition to subjective degrees of positive experience. Data from underweight and weight-restored AN will further allow us to probe starvation state-related effects. Results will advance our understanding of how reward stimuli are learned and the associated aberrant neural or physiological markers. This will yield a comprehensive mechanistic understanding of hedonic functioning in AN to rationally inform future novel treatment development.
455 studies on the registry are indexed under Anorexia Nervosa; 126 are open to participants now.
This study's planned enrollment of 90 is above the median of 72 across 135 observational studies indexed under Anorexia Nervosa.
Browse Anorexia Nervosa studies →Centre for Addiction and Mental Health is the lead sponsor of 328 studies on the registry; 51 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Investigators will enroll 90 female participants between the ages of 12 and 22 (30 with current anorexia nervosa - restricting type, 30 with a history of anorexia nervosa - restricting type, and 30 non-clinical healthy controls).
Inclusion Criteria:
AN-Restricting (AN-R) Group
Inclusion criteria:
BP and pulse measured at the day of the scan by the investigators
History of AN-Restricting Group:
Inclusion criteria:
Inclusion criteria:
Exclusion Criteria:
AN-R and History of AN-R groups:
Healthy controls:
All:
Meet Diagnostic and Statistical Manual (DSM-5) criteria for anorexia nervosa, restricting subtype
Behavioral: appetitive conditioning
* History of anorexia nervosa, restricting type - previously meeting full DSM-5 criteria. * Eating Disorder Examination Questionnaire (EDE-Q) ≤ 2 (within 1 standard deviation \[SD\] of community norms and lower than 1 standard deviation from clinical norms for female anorexia nervosa, restricting type populations)
Behavioral: appetitive conditioning
Healthy females from any racial or ethnic background, not meeting DSM-5 criteria for any psychiatric disorder.
Behavioral: appetitive conditioning
The investigators will examine acquisition and extinction of learned associations to positively-valenced, socially rewarding yet symptom-neutral infant laughter sounds in an appetitive conditioning paradigm. The investigators will also examine spontaneous recovery of this association 24 hours later when re-presented with these cues, and the reinstatement of this association when re-exposed to infant laughter.
Positive valence
A 10-point Likert scale will assess self-reported pleasantness and arousal for each conditioned stimulus, and unconditioned stimulus expectancy
Time frame: Day 1
Positive valence
A 10-point Likert scale will assess self-reported pleasantness and arousal for each conditioned stimulus, and unconditioned stimulus expectancy
Time frame: Day 2
Pupillary dilation
Measured with an eye-tracking camera
Time frame: Day 1
Pupillary dilation
Measured with an eye-tracking camera
Time frame: Day 2
Heart rate deceleration
Measured with an electrocardiogram
Time frame: Day 1
Heart rate deceleration
Measured with an electrocardiogram
Time frame: Day 2
Brain activation
Neural activation in reward circuits measured with functional magnetic resonance imaging
Time frame: Day 1
Brain activation
Neural activation in reward circuits measured with functional magnetic resonance imaging
Time frame: Day 2
Plan to share: No
This study is active, not recruiting, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Centre for Addiction and Mental Health