Anorexia Nervosa, Anxiety, Eating Disorders
Conditions
Brief summary
This study investigates excessive avoidance behaviors in patients with a diagnosis of Anorexia Nervosa (AN) compared to a healthy control group. The study further examines the role of reward (relief) as a putative factor in maintaining excessive avoidance behaviors in AN.
Detailed description
Anorexia Nervosa (AN) is a life-threatening mental disease with a disappointing treatment outcome. Fear of weight gain and diet restrictions are considered the core symptoms of AN. Although from a diagnostic perspective AN is conceptualized as an eating-related disorder connected to an extremely low Body Mass Index (BMI) and body image distortion, AN might represent a specific phenotype of anxiety disorders characterized by tenacious avoidance behaviors, especially the restrictive subtype. To date, avoidance in AN is often investigated as a general personality trait (e.g. harm avoidance) but poorly examined in its behavioral form (which is life-threatening, such as food-avoidance). Hence, the investigators will perform a systematic investigation of excessive avoidance behaviors within a laboratory setting. Within a learning perspective, the investigators will investigate excessive avoidance in a group of 30 AN patients and 30 healthy volunteers. To achieve this, a well-validated avoidance paradigm will be used. Most critically, the investigators will examine whether patients with a diagnosis of anorexia nervosa show persistent avoidance behaviors compared to a control group. Additionally, the investigators will examine if, in the anorexia group, higher subjective relief to successful omissions of negative events during avoidance learning predicts persistent (excessive) avoidance behaviors after fear extinction.
Interventions
BEHAVIORALBehavioral avoidance task
Behavioral task able to measure avoidance actions, US-expectancy, and reward-related indexes in different learning times
Sponsors
Bram Vervliet
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* For the AN group, patients need to be physically strong and sufficiently emotionally stable * For the healthy group, the investigators will recruit participants without a previous or current history of psychiatric, cardiovascular, neurological or other relevant disorder
Exclusion criteria
* For the AN group, the investigators will exclude patients who are insufficiently emotionally stable and/or physically weak to participate in the study as estimated by the treating physicians of the units on which the patients are admitted * Insufficient verbal skills to understand the questionnaires and the computer task * Participants who are pregnant or breastfeeding
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Button clicks during a red cue will be recorded as a measure of avoidance (binary response) | through study completion, an average of 1 year | To investigate whether, compared to healthy controls, individuals with a diagnosis of anorexia nervosa show excessive avoidance behaviors (frequent clicking to prevent the aversive stimulus). Repeated measure ANOVA (analysis of variance) will be employed to evaluate differences between groups. If data will violate the assumption of normality, mixed or generalize methods will be used. |
| Relief pleasantness ratings (Visual Analog Scale, from neutral [0] to very pleasant [100]) | through study completion, an average of 1 year | To investigate whether, compared to healthy controls, individuals with a diagnosis of anorexia nervosa show higher relief pleasantness during the omission of the aversive stimuli. The investigators will also test if such responses predict a return in avoidance behaviors (button click) after fear has been extinguished. Repeated measure ANOVA (analysis of variance) and multiple linear regressions will be employed to evaluate differences between groups. If data will violate the assumption of normality mixed or generalize methods will be used. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| US-Expectancy ratings (Likert scale from 0:no picture to 10:certainly a picture) | through study completion, an average of 1 year | To investigate whether, compared to healthy controls, individuals with a diagnosis of anorexia nervosa show higher US-expectancies during both avoidance learning and fear extinction learning. Repeated measure ANOVA (analysis of variance) will be employed to evaluate differences between groups. If data will violate the assumption of normality mixed or generalize methods will be used. |
| Eating Disorders Inventory [EDI] | through study completion, an average of 1 year | Higher scores at the EDI, and especially to the drive for thinness subscale, correlate with higher avoidance actions. |
| Distress Tolerance Scale [DTS] | through study completion, an average of 1 year | Lower scores at the DTS correlate with higher relief and higher avoidance actions |
Countries
Belgium
Contacts
Primary ContactLaurence Claes, Prof. Dr.
Backup ContactBram Vervliet, Prof. Dr.
Outcome results
None listed