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.
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.
Study Type
OBSERVATIONAL
Enrollment
100
Behavioral task able to measure avoidance actions, US-expectancy, and reward-related indexes in different learning times
Psychiatry | UZ Leuven campus Gasthuisberg
Leuven, Belgium
RECRUITINGUniversity of KU Leuven, Faculteit Psychologie en Pedagogische Wetenschappen
Leuven, Belgium
RECRUITINGButton clicks during a red cue will be recorded as a measure of avoidance (binary response)
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.
Time frame: through study completion, an average of 1 year
Relief pleasantness ratings (Visual Analog Scale, from neutral [0] to very pleasant [100])
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.
Time frame: through study completion, an average of 1 year
US-Expectancy ratings (Likert scale from 0:no picture to 10:certainly a picture)
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.
Time frame: through study completion, an average of 1 year
Eating Disorders Inventory [EDI]
Higher scores at the EDI, and especially to the drive for thinness subscale, correlate with higher avoidance actions.
Time frame: through study completion, an average of 1 year
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Distress Tolerance Scale [DTS]
Lower scores at the DTS correlate with higher relief and higher avoidance actions
Time frame: through study completion, an average of 1 year