Journal of Abnormal Psychology © 2017 American Psychological Association 2017, Vol. 126, No. 5, 540–551 0021-843X/17/$12.00 http://dx.doi.org/10.1037/abn0000242 The Impact of Acute Stress on the Neural Processing of Food Cues in Bulimia Nervosa: Replication in Two Samples Brittany Collins Lauren Breithaupt National Medical Center, Washington, DC George Mason University Jennifer E. McDowell and L. Stephen Miller James Thompson and Sarah Fischer University of Georgia George Mason University The impact of acute stress on the neural processing of food cues in bulimia nervosa (BN) is unknown, despite theory that acute stress decreases cognitive control over food and hence increases vulnerability to environmental triggers for binge eating. Thus, the goals of this manuscript were to explore the impact of acute stress on the neural processing of food cues in BN. In Study 1, 10 women with Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5; American Psychiatric Association, 2013) BN and 10 healthy controls participated in an fMRI paradigm examining the neural correlates of visual food cue processing pre and post an acute stress induction. Whole brain analysis indicated that women with BN exhibited significant decreases in activation in the precuneus, associated with self-referential processing, the paracingulate gyrus, and the anterior vermis of the cerebellum. Healthy controls exhibited increased activation in these regions in response to food cues poststress. In Study 2, 17 women with DSM–5 BN or otherwise specified feeding and eating disorder with BN symptoms participated in the same paradigm. A region of interest analysis replicated findings from Study 1. Replication of imaging findings in 2 different samples suggests the potential importance of these regions in relation to BN. Decreased activation in the precuneus, specifically, is consistent with models of BN that posit that binge eating serves as a concrete distraction from aversive internal stimuli. General Scientific Summary Binge eating in bulimia nervosa is often triggered by acute stress and serves as a distractor from aversive thoughts about the self. This study indicates that women with bulimia nervosa (BN) experience dampened response in the precuneus and heightened response in other regions when presented with food cues following acute stress. The results suggest a neurobiological basis for escape theories of emotion regulation in BN. Keywords: bulimia, neuroimaging, fMRI, stress, food cues Supplemental materials: http://dx.doi.org/10.1037/abn0000242.supp Bulimia nervosa (BN) is a disorder classified by recurrent episodes fluenced by shape and weight (American Psychiatric Associa- of binge eating, compensatory behavior via purging, excessive exer- tion, 2013). Emotion regulation models of BN suggests that cise, or extreme caloric restriction, and self-evaluation strongly in- binge eating reduces negative affect, and is thus negatively reinforced (Heatherton & Baumeister, 1991; Pearson, Wonder- lich, & Smith, 2015). The act of binge eating allows an indi- vidual to focus on a concrete, present focused stimulus that Brittany Collins, Department of Pediatric Neuropsychology, National Med- reduces awareness of aversive cognitions about the self (Heath- ical Center, Washington, DC; Lauren Breithaupt, Department of Psychology, erton & Baumeister, 1991). Negative affect may be triggered by George Mason University; Jennifer E. McDowell and L. Stephen Miller, self-comparison or aversive self-related cognitions (Pearson et Department of Psychology, University of Georgia; James Thompson and al., 2015). Consistent with these emotion regulation models, Sarah Fischer, Department of Psychology, George Mason University. several laboratory and ecological momentary assessment stud- This study was funded by the William and Barbara R. Owens Institute ies demonstrate that stress and negative affect increase prior to for Behavioral Research at the University of Georgia, The University of binge eating, with several studies also demonstrating that neg- Georgia Bioimaging Research Center, the John and Mary Franklin Foun- dation, and George Mason University. ative affect decreases directly following binge eating (Becker, Correspondence concerning this article should be addressed to Sarah Fischer, Smith, & Miller, 2016; Berg et al., 2014; Cardi, Lep- Fischer, Department of Psychology, George Mason University, MSN 3F5, panen, & Treasure, 2015; Smyth et al., 2007; but see Haedt- 4400 University Drive, Fairfax, VA 22030. E-mail: [email protected] Matt & Keel, 2011). 540 NEURAL PROCESSING OF FOOD CUES IN BULIMIA NERVOSA 541 Although this and other psychosocial models of binge eating are little is known about how viewing food cues during acute stress well-established, there is growing interest in the neurobiological affects functional responses in the brain. Studies utilizing fMRI to substrates of BN (Berner & Marsh, 2014; Kaye et al., 2013). There examine responses to both stress and food cues indicate that are few studies that examine the impact of acute negative emotion changes in BOLD signals are present in similar regions across or stress on the neural processing of food cues, however, and none acute stress conditions and food cue conditions (Hommer et al., that include individuals with BN (e.g., Born et al., 2010). This is 2013; Jastreboff et al., 2013). Those studies that have examined surprising, as acute stress increases risk for binge episodes in BOLD response to food cues directly following acute stress have individuals with BN, and the presence of food cues may increase suggest that limbic regions exhibit decreased response while pro- risk for lapses in restraint (e.g., Smyth et al., 2007; Wallis & cessing food cues under stress (Born et al., 2010). Hetherington, 2004). Thus, this pair of studies was designed to examine the impact of acute stress on the neural correlates of food Current Study cue reactivity and subjective response to food cues in women with BN. The goal of this research is to integrate premises from the Psychosocial models of binge eating in BN posit that acute emotion regulation theory of BN with neurobiological models, in stressors increase aversive self-related cognitions, negative affect, order to help develop a more complete understanding of how brain and avoidance of higher order cognition (Heatherton & Baumeis- function impacts psychopathology. ter, 1991; Pearson et al., 2015). In turn, self-control is depleted and previously rewarding food stimuli may become more salient Stress (Mather & Lighthall, 2012; Pearson et al., 2015). Given this, we anticipate that regions associated with self-referential cognition, Stress is understood to be “an experience in which the demands cognitive control and reward may exhibit dampened response to incurred by deviation from one’s normal state exceed one’s coping food cues following acute stress, whereas regions associated with resources,” (Lazarus, 1993, p. 32). Acute stress may be a partic- attention may exhibit increased response to these cues. ularly important trigger for binge eating in women with BN The goal of our current studies was to examine the neurobio- (Goldschmidt et al., 2014; Smyth et al., 2007). There are several logical response to food cues under conditions of acute stress in potential mechanisms via which acute stress may facilitate binge women with BN. Two studies were conducted using the same eating. Cognitive appraisals of stressful situations initiate a se- fMRI paradigm. Briefly, participants viewed a series of neutral quence of neurobiological events. These cognitive appraisals may cues, followed by a series of highly palatable food cues. Following be personally aversive, perhaps involving self-critical thinking an acute stress induction in the scanner, participants were exposed regarding how one may handle the stressor. This, in turn, may to a different series of highly palatable food cues. Following each motivate a desire to avoid. Although several brain regions are run, participants reported subjective levels of stress and craving for involved in the evaluation of stressful events, the precuneus plays food. The first study included 10 women with DSM–5 BN and 10 an important role in self-referential processing (Cavanna & noneating disordered women. Whole brain analyses of within- Trimble, 2006; Soares et al., 2013). Activity in this region is subject and between-subjects responses were selected because of associated with body shape concern in BN and with rumination in the exploratory nature of the research question. The second study non-ED samples (e.g., Hamilton, Farmer, Fogelman, & Gotlib, included 17 women with Diagnostic and Statistical Manual of 2015; Lee et al., 2014). These, among other studies, indicate that Mental Disorders (5th ed.; DSM–5; American Psychiatric Associ- this region plays a functional role in self-appraisal. Acute ego- ation, 2013) BN or an otherwise specified feeding and eating threatening stress may trigger a dampening response in this region disorder (OSFED) with BN symptoms. The regions showing sig- as resources are directed toward distracting external stimuli. nificant results from Study 1 were used to create a priori regions of Following cognitive appraisal, the physiological response to interest (ROI) for Study 2. Thus, we conducted analyses for the acute stress is initiated in the hypothalamic pituitary adrenal same paradigm on two different samples; a whole brain analysis in (HPA) axis (Dickerson & Kemeny, 2004; Ulrich-Lai & Herman, one sample, and