Role of oxytocin in attentional bias and reward-related food intake in binge eating disorder

01/08/2016 to 31/07/2018

Objective episodes of binge eating are the central symptom of binge eating disorder (BED; DSM-5; American Psychiatric Association [APA], 2013). Cognitive models of eating disorders (Williamson, White, York-Crowe, & Stewart, 2004) suggest that disorder-typical stimuli such as high caloric food activate selective information processes assumed to substantially contribute to the maintenance of pathological eating behavior (Wilson, Fairburn, Agras, Walsh, & Kraemer, 2002). In accordance, women with BED compared to overweight women without BED display increased attention towards food stimuli (Schag et al., 2013; Schmitz, Naumann, Biehl, & Svaldi, 2015; Schmitz, Naumann, Trentowska, & Svaldi, 2014; Svaldi, Tuschen-Caffier, Peyk, & Blechert, 2010). The neuropeptide oxytocin has been shown to control social cognition and social behavior as evidenced by studies in animals (Donaldson & Young, 2008; Insel, 2010) and humans (Heinrichs, von Dawans, & Domes, 2009; Meyer-Lindenberg, Domes, Kirsch, & Heinrichs, 2011). Notably, oxytocin has also been shown to specifically modulate the attentional food bias in women with anorexia nervosa (Kim et al., 2014). Moreover, intranasal oxytocin administration to the brain inhibits reward-driven snack intake in normal-weight healthy men (Ott et al., 2013). Therefore, the present project hypothesizes that oxytocin decreases selective attention to food stimuli and thereby reduces hedonic food intake in women with BED.
To this end, we plan to administer intranasal oxytocin in a double-blind, placebo-controlled, cross-over within-subject comparison to a group of women with BED and a weight- and age-matched group of women without lifetime eating disorder. Participants will be given a standardized meal prior to the drug administration. Subsequently, attention towards food stimuli will be assessed in a dot-probe task using reaction times and the eye-tracking methodology. Reward-driven food intake will be measured in the context of a taste test (Svaldi, Tuschen-Caffier, Trentowska, Caffier, & Naumann, 2014).
We will recruit a total of 42 women with BED (DSM-5) and 42 weight and age matched women without BED (control group; CG). Central outcome measures are (a) the attentional bias towards food stimuli (as measured by the dot-probe task), (b) calorie consumption in the taste test, and (c) the mediation of the impact of oxytocin on food intake by its effect on attentional food bias.