Neural Response to Catecholamine Depletion in Subjects Suffering From Bulimia Nervosa in Their Past and Healthy Controls

• Status: Suspended
• Trial end date: 2022-05-01
• Target enrollment: 0
• Participant gender: Female

Summary

Bulimia nervosa is a severe psychiatric disorder characterized by recurrent binge eating episodes followed by inappropriate compensatory behavior to prevent weight gain such as self-induced vomiting. With this project, the investigators want to investigate the role of the neurotransmitter dopamine in bulimia nervosa. Dopamine is reported to have an important influence on the neural reward system and is involved in the processing of gains and losses. The reward system is functionally connected to the individual perception of rewards in the environment. A previous study revealed that under catecholamine depletion including dopamine depletion women suffering from bulimia nervosa in their past reported mild bulimic symptoms and their reward processing became dysfunctional: their ability to use rewarding stimuli for task solving was diminished.

The aim of this study is to investigate the role of reduced dopamine availability in the development or maintaining of bulimia nervosa and in the dysfunctional processing of rewarding stimuli and negative visual information. Therefore, the investigators hypothesize that catecholamine depletion achieved by oral administration of alpha-methyl-paratyrosine (AMPT) will induce mild bulimic symptoms in females suffering from bulimia nervosa in their past. In addition, they will reveal dysfunctions in reward and emotional processing under catecholamine depletion. Using functional magnetic resonance imaging, the investigators propose that a reduced activation of the nucleus accumbens, a neural structure of the reward system, will be the neural correlate of this dysfunctional reward processing. Furthermore, the amygdala, a neural structure that is involved in emotional processing, will show a higher activation under catecholamine depletion. Genetic factors additionally have an influence on the dopaminergic system. Therefore, the investigators hypothesize that genetic factors, for example the COMT val-158-met polymorphism may have an effect on the behavioral and neural response to catecholamine depletion. In sum, this investigation may help to understand which changes in reward and emotional processing may lead to a reoccurrence of bulimic symptoms.

In future, the findings of this study may help to develop individual pharmacological and psychotherapeutical interventions to enhance the outcome of treatment.

• Phase: N/A
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: University of Bern
• Collaborators: University Hospital Inselspital, Berne; University of Zurich
• Treatments: alpha-Methyltyrosine; Diphenhydramine; Promethazine

Criteria

Inclusion Criteria:

• female

• age: 18-60

• caucasian ethnicity

• right handedness

• normal or corrected to normal vision and hearing performance

• remitted bulimic participants: have met the DSM IV criteria for bulimia nervosa in the past

• remitted bulimic participants: have been asymptomatic for at least1 month

• signed written informed consent

Exclusion Criteria

• healthy volunteers: any lifetime psychiatric diagnosis

• healthy volunteers: any lifetime psychiatric diagnosis in first-degree relatives

• no or impaired understanding of the tasks or the risks of the study

• medical or neurological illnesses likely to affect physiology or anatomy

• suicidal ideation or suicide attempts within the last 8 weeks

• current use of psychotropic drugs

• history of drug including alcohol and nicotine (not more than 10 cigarettes per day) abuse within 1 year or a lifetime history of alcohol or drug dependence (DSM IV criteria) longer than 2 years

• asthma

• glaucoma

• pyloroduodenal obstruction (gastrointestinal stenosis)

• current pregnancy

• current breast feeding

• cardiac pacemaker

• heart or brain surgery

• metallic implants and alien objects in the body

• tattoos on head, neck or shoulders as well as permanent make-up

• claustrophobia