Self-referential processing in anorexia nervosa.

OBJECTIVE: Anorexia nervosa (AN) is a serious psychiatric illness associated with significant medical and psychiatric comorbidity and impairment. Theoretical models of AN and self-report studies suggest that negative self-evaluation (i.e., low self-esteem) is related to the development and maintenance of AN. The goal of this study was to extend findings from self-report methodology using a neurocognitive task that probes self-evaluation implicitly and explicitly. METHOD: We compared female adolescent and adult patients with AN (n = 35) and healthy controls (HC, n = 38) on explicit (i.e., endorsement of words as self-relevant), implicit (recall, recognition, reaction time), and composite (i.e., valence index, bias score, drift rates) indices of self-evaluation. We applied a drift-diffusion model to compute the drift rates, reflecting participants' decision-making process as to whether words were self-relevant. The association between self-evaluation indices and eating disorder severity was examined. RESULTS: There were significant Group × Condition interaction effects for all explicit and implicit measures (all p's ≤ .01), where the AN group endorsed, recalled, and recognized more negative relative to positive words than HC. The AN group had more negative valence index and bias scores, and slower drift rate away from negative words, reflecting more negative self-evaluation. The finding for recall was attenuated when individuals with depression were excluded. Measures of self-evaluation bias were not related to eating disorder severity. DISCUSSION: Using a neurocognitive approach that includes explicit and implicit indices of bias, results suggest that patients with AN have more negative self-evaluation. Due to the cross-sectional design, additional studies are needed to further evaluate directionality. PUBLIC SIGNIFICANCE: Negative self-evaluation/low self-esteem is thought to contribute to eating disorder symptoms. Findings of this study using a neurocognitive task to probe self-evaluation suggested that individuals with anorexia nervosa have more negative self-evaluation, reflected by endorsing and remembering more negative (than positive) words compared to healthy controls, and doing so faster. Targeting the construct of negative self-evaluation in treatment of AN may be warranted.

Eating disorder symptom non-endorsers in hospitalised patients with anorexia nervosa: Who are they?

OBJECTIVE: Impaired insight and illness denial are common in anorexia nervosa (AN). Missing an AN diagnosis may delay treatment and negatively impact outcomes. METHOD: The current retrospective study examined the prevalence and characteristics of AN symptom non-endorsement (i.e., scoring within the normal range on the Eating Disorder Examination Questionnaire [EDE-Q] or the Eating Disorder Examination [EDE] interview) in three independent samples of hospitalised patients with AN (N1 = 154; N2 = 300; N3 = 194). A qualitative chart review of a subsample of non-endorsers (N4 = 32) extracted reports of disordered eating behaviours observed by the treatment team. RESULTS: The prevalence of non-endorsement ranged from 11% to 34% across sites. Non-endorsers were more likely to be diagnosed with AN restricting type (AN-R) and reported fewer symptoms of co-occurring psychopathology than endorsers. Groups benefitted equally from treatment. The qualitative chart review indicated that objective symptoms of AN were recorded by staff in over 90% of non-endorsers. CONCLUSIONS: Eating disorder symptom assessments using the EDE-Q or EDE may miss symptomatology in up to a third of individuals hospitalised with AN. This study highlights the potential utility of multi-modal assessment including patient interviews, collateral informants, and behavioural observation to circumvent non-endorsement.

Reduced dorsal fronto-striatal connectivity at rest in anorexia nervosa.

BACKGROUND: Anorexia nervosa (AN) is a serious psychiatric illness that remains difficult to treat. Elucidating the neural mechanisms of AN is necessary to identify novel treatment targets and improve outcomes. A growing body of literature points to a role for dorsal fronto-striatal circuitry in the pathophysiology of AN, with increasing evidence of abnormal task-based fMRI activation within this network among patients with AN. Whether these abnormalities are present at rest and reflect fundamental differences in brain organization is unclear. METHODS: The current study combined resting-state fMRI data from patients with AN (n = 89) and healthy controls (HC; n = 92) across four studies, removing site effects using ComBat harmonization. First, the a priori hypothesis that dorsal fronto-striatal connectivity strength - specifically between the anterior caudate and dlPFC - differed between patients and HC was tested using seed-based functional connectivity analysis with small-volume correction. To assess specificity of effects, exploratory analyses examined anterior caudate whole-brain connectivity, amplitude of low-frequency fluctuations (ALFF), and node centrality. RESULTS: Compared to HC, patients showed significantly reduced right, but not left, anterior caudate-dlPFC connectivity (p = 0.002) in small-volume corrected analyses. Whole-brain analyses also identified reduced connectivity between the right anterior caudate and left superior frontal and middle frontal gyri (p = 0.028) and increased connectivity between the right anterior caudate and right occipital cortex (p = 0.038). No group differences were found in analyses of anterior caudate ALFF and node centrality. CONCLUSIONS: Decreased coupling of dorsal fronto-striatal regions indicates that circuit-based abnormalities persist at rest and suggests this network may be a potential treatment target.

Neurodevelopmental Sequelae of Anorexia Nervosa.

Anorexia nervosa (AN) is a severe mental illness with substantial morbidity and mortality. The central, salient disturbance in AN is restriction of food intake, leading to inappropriately low body weight. Onset of illness is most common during mid-adolescence, and approximately 1% of female individuals are affected over a lifetime, across all socioeconomic classes.1 Despite advancements in treatment for adolescents with AN, remission rates remain disappointing-less than 50% of teens typically respond to initial treatment.2 Among those who achieve remission, subsequent relapses of AN are common, as is the presence of affective disorders later in life.2.

Change in food choice during acute treatment and the effect on longer-term outcome in patients with anorexia nervosa.

BACKGROUND: Restriction of food intake is a central pathological feature of anorexia nervosa (AN). Maladaptive eating behavior and, specifically, limited intake of calorie-dense foods are resistant to change and contribute to poor long-term outcomes. This study is a preliminary examination of whether change in food choices during inpatient treatment is related to longer-term clinical course. METHODS: Individuals with AN completed a computerized Food Choice Task at the beginning and end of inpatient treatment to determine changes in high-fat and self-controlled food choices. Linear regression and longitudinal analyses tested whether change in task behavior predicted short-term outcome (body mass index [BMI] at discharge) and longer-term outcome (BMI and eating disorder psychopathology). RESULTS: Among 88 patients with AN, BMI improved significantly with hospital treatment (p < 0.001), but Food Choice Task outcomes did not change significantly. Change in high-fat and self-controlled choices was not associated with BMI at discharge (r = 0.13, p = 0.22 and r = 0.10, p = 0.39, respectively). An increase in the proportion of high-fat foods selected (ß = 0.91, p = 0.02) and a decrease in the use of self-control (ß = -1.50, p = 0.001) predicted less decline in BMI over 3 years after discharge. CONCLUSIONS: Short-term treatment is associated with improvement in BMI but with no significant change, on average, in choices made in a task known to predict actual eating. However, the degree to which individuals increased high-fat choices during treatment and decreased the use of self-control over food choice were associated with reduced weight loss over the following 3 years, underscoring the need to focus on changing eating behavior in treatment of AN.

Psilocybin for anorexia nervosa: If it helps, let's learn how.

Existing treatments for adults with anorexia nervosa (AN) have limited effectiveness. AN is a brain-based disorder with behavioral and cognitive features leading to severe undernourishment. Peck et al. conducted a small open trial suggesting safety and tolerability of psilocybin for AN,1 opening an avenue for further investigation into the neural mechanisms involved.

The next stages of treatment-oriented research: Commentary on Wade et al. (2023).

Treatments for eating disorders have established benefits; yet, current psychotherapies focus specifically on the cognitions and behaviors of the eating disorder. Wade et al. (2023) propose that the myriad symptoms and disorders that occur together with eating disorders merit specific attention in treatment research protocols. We seek to amplify the authors' call to take a fresh look at the characterization of eating disorders, and the need for treatment research to consider both the role of symptoms that occur as part and parcel of an eating disorder (such as mood, anxiety, and obsessionality) and the role of co-occurring disorders (such as obsessive-compulsive disorder and substance use disorders). We discuss additional aspects in the care of patients with eating disorders that were beyond the scope of Wade et al., such as the impact of systems of care, and consideration of medication trials. We propose that current research priorities (mechanism-based treatment development, transdiagnostic symptoms, and patient perspectives) can be leveraged to advance treatment research and develop a systematic approach to evaluation and treatment planning.

Perspectives on relapse prevention following intensive treatment of anorexia nervosa: A focus group study.

OBJECTIVE: Including the perspectives of individuals with lived experience of mental health issues is a critical step in research and treatment development. Focus groups with patients with a history of treatment for anorexia nervosa (AN) were conducted in anticipation of a clinical trial of Relapse Prevention and Changing Habits (REACH+). METHODS: Seven female adults (23-51 years) who had previously received inpatient treatment for AN, now in remission, participated in one of two semistructured focus groups. Rapid qualitative analysis was used to examine participants' contributions and identify common topics. RESULTS: Transcript analysis yielded three topics related to relapse prevention: (1) recovery aids, including a sense of agency in treatment decisions and finding new interests/passions, (2) recovery hindrances, such as lack of access to care, and (3) identification of members of support system. Aspects of REACH+ received positive feedback, such as continuity of care from the inpatient setting and the use of telehealth. Viewpoints differed with respect to the helpfulness of obtaining patient weights in treatment. The REACH+ online platform received positive comments regarding content and usability, as well as suggestions for additional content. DISCUSSION: Qualitative feedback from patients with a history of AN highlighted the value of engaging patients in their own treatment decisions, as well as in treatment design and innovation. Within this small group, there were differences of opinion about treatment components, specifically weight assessment, that suggest the need for further data. User-centered design provides opportunities to improve the acceptability and, therefore, dissemination of novel treatments. PUBLIC SIGNIFICANCE: Relapse prevention is a critical treatment need for patients with anorexia nervosa, as this illness too often follows a protracted course. There are challenges in both obtaining specialized care and in retaining patients in treatment. Here, patient perspectives on these challenges offer input to allow for optimization of relapse prevention treatment. Shared decision-making may be particularly valuable to support an individual's sense of agency and engagement in care.

Integrating aspects of affect, reward, and cognition to develop more comprehensive models of binge-eating pathology.

Reward-related processes are an increasing focus of eating disorders research. Although evidence suggests that numerous distinct reward processes may contribute to eating pathology (e.g., reward learning and delay discounting), existing etiological models of reward dysfunction tend to focus on only a limited number of reward processes, and frequently lack specificity when identifying the individual reward processes hypothesized to contribute to dysregulated eating behavior. Moreover, existing theories have been limited in their integration of reward-related processes with other demonstrated risk and maintenance factors for eating disorders (e.g., affect and cognition), potentially contributing to underdeveloped models of eating pathology. In this article, we highlight five distinct reward processes with theorized or demonstrated relevance to eating disorders involving binge-eating, followed by a review of two well-established risk/maintenance factors for binge-eating pathology. We then introduce two novel models of binge eating onset and maintenance that integrate these factors (i.e., the Affect, Reward, Cognition models), and discuss methods for testing each of the models in future research. Ultimately, we hope that the proposed models provide a springboard for the continued evolution of more precise and comprehensive theories of reward dysfunction in the eating disorders, as well as the development of novel intervention approaches. PUBLIC SIGNIFICANCE STATEMENT: Eating disorders are associated with abnormalities in multiple domains of reward functioning. However, models of reward dysfunction within the eating disorders have not been well-integrated with prominent models of affect and cognition. This article presents two novel models of onset and maintenance for binge-eating pathology, which attempt to integrate observed reward abnormalities with other affective and cognitive processes implicated in binge-type eating disorders.

Large-Scale Exploration of Whole-Brain Structural Connectivity in Anorexia Nervosa: Alterations in the Connectivity of Frontal and Subcortical Networks.

BACKGROUND: Anorexia nervosa (AN) is characterized by disturbances in cognition and behavior surrounding eating and weight. The severity of AN combined with the absence of localized brain abnormalities suggests distributed, systemic underpinnings that may be identified using diffusion-weighted magnetic resonance imaging and tractography to reconstruct white matter pathways. METHODS: Diffusion-weighted magnetic resonance imaging data acquired from female patients with AN (n= 147) and female healthy control (HC) participants (n = 119), ages 12 to 40 years, were combined across 5 studies. Probabilistic tractography was completed, and full-cortex connectomes describing streamline counts between 84 brain regions were generated and harmonized. Graph theory methods were used to describe alterations in network organization in AN. The network-based statistic tested between-group differences in brain subnetwork connectivity. The metrics strength and efficiency indexed the connectivity of brain regions (network nodes) and were compared between groups using multiple linear regression. RESULTS: Individuals with AN, relative to HC peers, had reduced connectivity in a network comprising subcortical regions and greater connectivity between frontal cortical regions (p < .05, familywise error corrected). Node-based analyses indicated reduced connectivity of the left hippocampus in patients relative to HC peers (p < .05, permutation corrected). Severity of illness, assessed by body mass index, was associated with subcortical connectivity (p < .05, uncorrected). CONCLUSIONS: Analyses identified reduced structural connectivity of subcortical networks and regions, and stronger cortical network connectivity, among individuals with AN relative to HC peers. These findings are consistent with alterations in feeding, emotion, and executive control circuits in AN, and may direct hypothesis-driven research into mechanisms of persistent restrictive eating behavior.

Eating behavior in atypical anorexia nervosa.

OBJECTIVE: Atypical anorexia nervosa (AN) has been increasingly identified in the community and in clinical settings. Initial studies indicate that psychological symptoms are similar or more severe among patients with atypical AN, as compared with AN. This study examined whether eating behavior differed among patients with AN (n = 98), patients with atypical AN (n = 18), and healthy controls (HC, n = 75). METHOD: Adults and adolescents chose what to eat from a standardized, laboratory-based multi-item meal. Total intake, macronutrient composition, diet variety, and energy density were compared between groups. RESULTS: Both AN and atypical AN severely restricted caloric intake as compared with HC (431 ± 396 kcal and 340 ± 338 kcal vs. 879 ± 350 kcal, F2,188  = 35.4, p < .001). Individuals with AN and atypical AN did not differ in the mean intake of total calories or percentage of calories from fat (15.2 ± 25.2% vs. 11.5 ± 16.9%). DISCUSSION: This study demonstrates that individuals with atypical AN are at least as restrictive in their food intake as individuals with AN, and the restriction of dietary fat is particularly notable. Examination of eating behavior in a larger sample would be useful to replicate these findings. The current study highlights the need to understand maladaptive eating behavior in atypical AN in order to develop appropriate treatment recommendations. PUBLIC SIGNIFICANCE: Atypical anorexia nervosa is emerging as a prevalent eating disorder in community and clinical populations. The findings that patients with atypical anorexia nervosa limit calorie and fat intake in a pattern similar to that of patients with anorexia nervosa highlights the need for research to identify appropriate treatment strategies for normalization of eating patterns.

Early Course of Symptom Development in Anorexia Nervosa.

PURPOSE: Anorexia nervosa (AN) commonly begins in adolescence; however, detailed knowledge of symptom trajectories, including their temporal sequence, is less well elucidated. The purpose of the present study is to describe the onset and duration of disordered eating behaviors prior to a diagnosis of AN, examine concordance between child and parent report, and examine the relationships between timing of symptom onset and illness severity. METHODS: Seventy-one adolescents (ages 12-18 years) and their parents were interviewed about dieting, restriction, loss of control/binge eating, purging, excessive/compulsive exercise, weight history, and amenorrhea. Body mass index percentiles were calculated, and adolescents completed the Eating Disorder Examination-Questionnaire. RESULTS: Restriction, being underweight, dieting, and excessive exercise were reported by most of the sample; purging, loss-of-control eating, and having been overweight were reported by less than a third. Dieting typically emerged first, on average around age 14; the remainder of behaviors tended to emerge between ages 14 and 14½; and average age of formal diagnosis was slightly over 15 years. Dyads had good agreement regarding presence and timing of all behaviors except for dieting, for which children reported about 6 months earlier onset/longer duration, compared to parents. Although older age at interview was associated with lower body mass index percentile and higher EDE-Q score, neither age of onset nor duration was associated with severity when controlling for current age. DISCUSSION: Teens and parents describe a similar sequence of behavior changes leading up to a diagnosis of AN that typically begins with dieting and occurs over an approximate 1- to 1½-year period. Querying teens and parents about eating behavior changes may aid in identification and early intervention in AN; adolescents with normal weight who engage in persistent dieting or restrictive eating may warrant more frequent weight monitoring.

Optimizing relapse prevention and changing habits (REACH+) in anorexia nervosa.

INTRODUCTION: Relapse rates in anorexia nervosa (AN) are high, even after full weight restoration. This study aims to develop a relapse prevention treatment that specifically addresses persistent maladaptive behaviors (habits). Relapse Prevention and Changing Habits (REACH+) aims to support patients in developing routines that promote weight maintenance, encourage health, and challenge habits that perpetuate illness. The clinical trial design uses the Multiphase Optimization STrategy (MOST) framework to efficiently identify which components of treatment contribute to positive outcomes. METHODS: Participants will be 60 adults with AN who have achieved weight restoration in an inpatient setting. Treatment will consist of 6 months of outpatient telehealth sessions. REACH+ consists of behavior, cognitive, and motivation components, as well as food monitoring and a skill consolidation phase. A specialized online platform extends therapy between sessions. Participants will be randomly assigned to different versions of each component in a fractional factorial design. Outcomes will focus on maintenance of remission, measured by rate of weight loss and end-of-trial status. Interventions that contribute to remission will be included in an optimized treatment package, suitable for a large-scale clinical trial of relapse prevention in AN.

Eating disorders in the U.S. Medicare population.

OBJECTIVE: The social and economic burden of eating disorders is significant and often financially devastating. Medicare is the largest public insurer in the United States and provides coverage for older adults and some disabled individuals. This study explores prevalence, sociodemographic and clinical characteristics, and health care spending for Medicare enrollees with eating disorders. METHOD: A cross-sectional study was conducted with the nationally representative 20% sample of 2016 Medicare inpatient, outpatient, carrier, and home health fee-for-service claims and Medicare Advantage encounter records. Sociodemographic characteristics and comorbid somatic conditions were compared between individuals with versus without an eating disorder diagnosis. Mean spending was compared overall and separately for inpatient, outpatient, home health, and pharmacy claims. RESULTS: The sample included 11,962,287 Medicare enrollees of whom 0.15% had an eating disorder diagnosis. Compared to those without a 2016 eating disorder diagnosis, a greater proportion of individuals with an eating disorder were female (73.8% vs. 54.3%), under age 65 (41.6% vs. 15.5%), and dually eligible for Medicaid due to disability or low-income qualification (48.0% vs. 19.6%). Individuals with eating disorders had higher rates of comorbid conditions, with the greatest differences in cardiac arrythmias (35.3% vs. 19.9%), arthritis (40.1% vs. 26.6%), and thyroid conditions (32.2% vs. 19.4%). Spending was higher for enrollees with eating disorders compared to those without overall ($29,456 vs. $7,418) and across settings. DISCUSSION: The findings establish that eating disorders occur in the Medicare population, and that enrollees with these illnesses have risk factors associated with significant healthcare spending and adverse health outcomes.

Restrictive eating across a spectrum from healthy to unhealthy: behavioral and neural mechanisms.

BACKGROUND: Restriction of food intake is a central feature of anorexia nervosa (AN) and other eating disorders, yet also occurs in the absence of psychopathology. The neural mechanisms of restrictive eating in health and disease are unclear. METHODS: This study examined behavioral and neural mechanisms associated with restrictive eating among individuals with and without eating disorders. Dietary restriction was examined in four groups of women (n = 110): healthy controls, dieting healthy controls, patients with subthreshold (non-low weight) AN, and patients with AN. A Food Choice Task was administered during fMRI scanning to examine neural activation associated with food choices, and a laboratory meal was conducted. RESULTS: Behavioral findings distinguished between healthy and ill participants. Healthy individuals, both dieting and non-dieting, chose significantly more high-fat foods than patients with AN or subthreshold AN. Among healthy individuals, choice was primarily influenced by tastiness, whereas, among both patient groups, healthiness played a larger role. Dorsal striatal activation associated with choice was most pronounced among individuals with AN and was significantly associated with selecting fewer high-fat choices in the task and lower caloric intake in the meal the following day. CONCLUSIONS: A continuous spectrum of behavior was suggested by the increasing amount of weight loss across groups. Yet, data from this Food Choice Task with fMRI suggest there is a behavioral distinction between illness and health, and that the neural mechanisms underlying food choice in AN are distinct. These behavioral and neural mechanisms of restrictive eating may be useful targets for treatment development.

Neural Representations of Food-Related Attributes in the Human Orbitofrontal Cortex during Choice Deliberation in Anorexia Nervosa.

Decisions about what to eat recruit the orbitofrontal cortex (OFC) and involve the evaluation of food-related attributes such as taste and health. These attributes are used differently by healthy individuals and patients with disordered eating behavior, but it is unclear whether these attributes are decodable from activity in the OFC in both groups and whether neural representations of these attributes are differentially related to decisions about food. We used fMRI combined with behavioral tasks to investigate the representation of taste and health attributes in the human OFC and the role of these representations in food choices in healthy women and women with anorexia nervosa (AN). We found that subjective ratings of tastiness and healthiness could be decoded from patterns of activity in the OFC in both groups. However, health-related patterns of activity in the OFC were more related to the magnitude of choice preferences among patients with AN than healthy individuals. These findings suggest that maladaptive decision-making in AN is associated with more consideration of health information represented by the OFC during deliberation about what to eat.SIGNIFICANCE STATEMENT An open question about the OFC is whether it supports the evaluation of food-related attributes during deliberation about what to eat. We found that healthiness and tastiness information was decodable from patterns of neural activity in the OFC in both patients with AN and healthy controls. Critically, neural representations of health were more strongly related to choices in patients with AN, suggesting that maladaptive overconsideration of healthiness during deliberation about what to eat is related to activity in the OFC. More broadly, these results show that activity in the human OFC is associated with the evaluation of relevant attributes during value-based decision-making. These findings may also guide future research into the development of treatments for AN.

Use of high-frequency repetitive transcranial magnetic stimulation to probe the neural circuitry of food choice in anorexia nervosa: A proof-of-concept study.

Repetitive transcranial magnetic stimulation (rTMS) is used to modulate neural systems and provides the opportunity for experimental tests of hypotheses regarding mechanisms underlying anorexia nervosa (AN). The present pilot study has investigated whether high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) to a region of the right dorsolateral prefrontal cortex (DLPFC) might be associated with change in food selection among adult inpatients with AN. Ten women received one session of sham and one session of HF-rTMS targeting the right DLPFC while completing a computerized Food Choice Task. Compared to sham, HF-rTMS was associated with changes in food ratings and food choice: inpatients reported higher healthiness ratings of low- and high-fat foods and selected a significantly greater proportion of high-fat foods over a neutrally rated reference item while receiving HF-rTMS. Findings suggest that HF-rTMS to the right DLPFC was associated with a reduction of fat avoidance on a food choice task among inpatients with AN and provide additional support for the possibility that this region, and related neural circuits, may underlie restrictive food choice. Research using rTMS to experimentally test neural mechanisms is needed to elucidate the underpinnings of AN and supports the development of novel treatment targets.

Associations between mealtime anxiety and food intake in anorexia nervosa.

OBJECTIVE: A salient disturbance in anorexia nervosa (AN) is the persistent restriction of food intake. Eating behavior in AN is thought to be influenced by anxiety. The current study probed associations between mealtime anxiety and food intake among individuals with AN and healthy comparison individuals (HC). METHOD: Data were combined across three studies (total of 92 AN and 78 HC) for secondary data analysis. Participants completed a multiitem laboratory buffet meal and visual analogue scale assessments of pre-meal and post-meal anxiety. Linear regression models assessed the association between mealtime anxiety and calorie and fat intake at the meal, and whether associations differed by diagnostic group. RESULTS: Among individuals with AN, pre-meal anxiety was significantly associated with reduced calorie intake and reduced consumption of calories from fat at the meal; these associations were not observed among HC. There was no evidence for an association between calorie/fat intake at the meal and post-meal anxiety in either group. DISCUSSION: Treatments that target mealtime anxiety may improve eating and nourishment among individuals with AN. Interventions like exposure therapy that provide skills in overcoming mealtime anxiety might be enhanced by informing patients that post-meal anxiety is not related to intake.

Exploring Neural Mechanisms Related to Cognitive Control, Reward, and Affect in Eating Disorders: A Narrative Review of FMRI Studies.

Studies using functional magnetic resonance imaging (fMRI) have contributed to our understanding of possible neural abnormalities among individuals with eating disorders. Many of these studies have focused on three domains: 1) cognitive control, 2) reward processing, and 3) affective processing. This review attempts to summarize the recent fMRI findings across these domains among the most well-characterized eating disorders: anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Though the literature is a bit murky, a few major themes have emerged. Cognitive control systems are affected among individuals across eating disorder diagnoses, but effects seem least pronounced in AN. Specifically, individuals with all eating disorders appear to show decreased prefrontal activation during cognitive control, but there is less evidence in AN linking decreased prefrontal activation with behavior. There is some evidence that the reinforcing value of food is reduced in AN, but individuals with BN and BED show hyperactivation to rewarding food-related stimuli, suggesting the reinforcing value of food may be enhanced. However, more complex reward processing paradigms show that individuals with BN and BED exhibit hypoactivation to reward anticipation and provide mixed results with regards to reward receipt. There are fewer neuroimaging findings related to affective processing, yet behavioral findings suggest affective processing is important in understanding eating disorders. Though the extant literature is complicated, these studies represent a foundation from which to build and provide insight into potential neurobiological mechanisms that may contribute to the pathophysiology of eating disorders.

Changes in brain and behavior during food-based decision-making following treatment of anorexia nervosa.

BACKGROUND: Anorexia nervosa is a severe illness with a high mortality rate, driven in large part by severe and persistent restriction of food intake. A critical challenge is to identify brain mechanisms associated with maladaptive eating behavior and whether they change with treatment. This study tested whether food choice-related caudate activation in anorexia nervosa changes with treatment. METHODS: Healthy women (n = 29) and women hospitalized with anorexia nervosa (n = 24), ages 18 to 40 years, completed a Food Choice Task during fMRI scanning at two timepoints. Among patients, procedures occurred upon hospital admission (Time 1) and again after patients had gained to normal weight (Time 2). Healthy controls were tested twice at an interval group-matched to patients. Choice-related caudate activation was assessed at each timepoint, using parametric analyses in an a priori region of interest. RESULTS: Among patients, the proportion of high-fat foods selected did not change over time (p's > 0.47), but decreased neural activity in the caudate after treatment was associated with increased selection of high-fat foods (r23 = - 0.43, p = 0.037). Choice-related caudate activation differed among women with anorexia nervosa vs healthy control women at Time 1 (healthy control: M = 0.15 ± 0.87, anorexia nervosa: M = 0.70 ± 1.1, t51 = - 2.05, p = 0.045), but not at Time 2 (healthy control: M = 0.18 ± 1.0, anorexia nervosa: M = 0.37 ± 0.99, t51 = - 0.694, p = 0.49). CONCLUSIONS: Caudate activity was more strongly associated with decisions about food among individuals with anorexia nervosa relative to healthy comparison individuals prior to treatment, and decreases in caudate engagement among individuals with anorexia nervosa undergoing treatment were associated with increases in high-fat food choices. The findings underscore the need for treatment development that more successfully alters both eating behavior and the neural mechanisms that guide it.