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

目的暴饮暴食是暴饮暴食障碍的中心症状(Bed；DSM-5；美国精神病学协会[APA]，2013)。饮食失调的认知模型(Williamson，White，York-Crowe，&Stewart，2004)表明，饮食失调的典型刺激，如高热量食物，激活了选择性的信息加工，被认为对病理性饮食行为的维持有很大贡献(Wilson，Fairburn，Agas，Walsh，&Kraemer，2002)。与没有床的超重女性相比，有床的女性表现出对食物刺激的更多关注(Schag等人，2013；Schmitz，Naumann，Biehl，&Svaldi，2015；Schmitz，Naumann，Trentowska，&Svaldi，2014；Svaldi，Tuschen-Caffier，Peyk，&Blechert，2010)。在动物(Donaldson&Young，2008；Insel，2010)和人类(Heinrichs，von Dawans，&Domes，2009；Meyer-Lindenberg，Domes，Kirsch，&Heinrichs，2011)上的研究证明，神经肽催产素可以控制社会认知和社会行为。值得注意的是，催产素也被证明可以专门调节患有神经性厌食症的女性的注意食物偏向(Kim等人，2014年)。此外，对正常体重健康男性的催产素鼻腔给药抑制了奖励驱动的零食摄入(Ott等人，2013年)。因此，本项目假设催产素减少了对食物刺激的选择性注意，从而减少了卧床妇女的享乐食物摄入量。为此，我们计划在双盲、安慰剂对照、受试者内交叉对照的情况下，对一组卧床的女性和一组体重和年龄匹配的没有终生进食障碍的女性进行鼻腔注射催产素。参与者在接受药物管理之前将获得标准化的膳食。随后，将使用反应时和眼球跟踪方法在点探测任务中评估对食物刺激的注意力。奖励驱动的食物摄入量将在品尝测试的背景下进行衡量(Svaldi，Tuschen-Caffier，Trentowska，Caffier，&Naumann，2014)。我们将招募42名卧床妇女(DSM-5)和42名体重和年龄匹配的无床妇女(对照组)。中心结果测量是(A)对食物刺激的注意偏向(通过点探测任务来测量)，(B)品尝测试中的卡路里消耗，以及(C)催产素对食物摄入量的影响通过其对注意食物偏向的影响来中介。

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.