Fear of food as a treatment target: exposure and response prevention for anorexia nervosa in an open series

Can Interoception Improve the Pragmatic Search for Biomarkers in Psychiatry?

Disrupted interoception is a prominent feature of the diagnostic classification of several psychiatric disorders. However, progress in understanding the interoceptive basis of these disorders has been incremental, and the application of interoception in clinical treatment is currently limited to panic disorder. To examine the degree to which the scientific community has recognized interoception as a construct of interest, we identified and individually screened all articles published in the English language on interoception and associated root terms in Pubmed, Psychinfo, and ISI Web of Knowledge. This search revealed that interoception is a multifaceted process that is being increasingly studied within the fields of psychiatry, psychology, neuroscience, and biomedical science. To illustrate the multifaceted nature of interoception, we provide a focused review of one of the most commonly studied interoceptive channels, the cardiovascular system, and give a detailed comparison of the most popular methods used to study cardiac interoception. We subsequently review evidence of interoceptive dysfunction in panic disorder, depression, somatic symptom disorders, anorexia nervosa, and bulimia nervosa. For each disorder, we suggest how interoceptive predictions constructed by the brain may erroneously bias individuals to express key symptoms and behaviors, and outline questions that are suitable for the development of neuroscience-based mental health interventions. We conclude that interoception represents a viable avenue for clinical and translational research in psychiatry, with a well-established conceptual framework, a neural basis, measurable biomarkers, interdisciplinary appeal, and transdiagnostic targets for understanding and improving mental health outcomes.

Altered sensitization patterns to sweet food stimuli in patients recovered from anorexia and bulimia nervosa

Recent studies show that higher-order appetitive neural circuitry may contribute to restricted eating in anorexia nervosa (AN) and overeating in bulimia nervosa (BN). The purpose of this study was to determine whether sensitization effects might underlie pathologic eating behavior when a taste stimulus is administered repeatedly. Recovered AN (RAN, n=14) and BN (RBN, n=15) subjects were studied in order to avoid the confounding effects of altered nutritional state. Functional magnetic resonance imaging (fMRI) measured higher-order brain response to repeated tastes of sucrose (caloric) and sucralose (non-caloric). To test sensitization, the neuronal response to the first and second administration was compared. RAN patients demonstrated a decreased sensitization to sucrose in contrast to RBN patients who displayed the opposite pattern, increased sensitization to sucrose. However, the latter was not as pronounced as in healthy control women (n=13). While both eating disorder subgroups showed increased sensitization to sucralose, the healthy controls revealed decreased sensitization. These findings could reflect on a neuronal level the high caloric intake of RBN during binges and the low energy intake for RAN. RAN seem to distinguish between high energy and low energy sweet stimuli while RBN do not.

Abnormal eating behavior in video-recorded meals in anorexia nervosa

OBJECTIVE

Eating behavior during meals in anorexia nervosa (AN) has long been noted to be abnormal, but little research has been done carefully characterizing these behaviors. These eating behaviors have been considered pathological, but are not well understood. The current study sought to quantify ingestive and non-ingestive behaviors during a laboratory lunch meal, compare them to the behaviors of healthy controls (HC), and examine their relationships with caloric intake and anxiety during the meal.

METHOD

A standardized lunch meal was video-recorded for 26 individuals with AN and 10 HC. Duration, frequency, and latency of 16 mealtime behaviors were coded using computer software. Caloric intake, dietary energy density (DEDS), and anxiety were also measured.

RESULTS

Nine mealtime behaviors were identified that distinguished AN from HC: staring at food, tearing food, nibbling/picking, dissecting food, napkin use, inappropriate utensil use, hand fidgeting, eating latency, and nibbling/picking latency. Among AN, a subset of these behaviors was related to caloric intake and anxiety.

DISCUSSION

These data demonstrate that the mealtime behaviors of patients with AN and HC differ significantly, and some of these behaviors may be associated with food intake and anxiety. These mealtime behaviors may be important treatment targets to improve eating behavior in individuals with AN.

Does compulsive behavior in Anorexia Nervosa resemble an addiction? A qualitative investigation

The characteristic relentless self-starvation behavior seen in Anorexia Nervosa (AN) has been described as evidence of compulsivity, with increasing suggestion of parallels with addictive behavior. This study used a thematic qualitative analysis to investigate the parallels between compulsive behavior in AN and Substance Use Disorders (SUD). Forty individuals currently suffering from AN completed an online questionnaire reflecting on their experience of compulsive behavior in AN. Eight main themes emerged from thematic qualitative analysis; compulsivity as central to AN, impaired control, escalating compulsions, emotional triggers, negative reactions, detrimental continuation of behavior, functional impairment, and role in recovery. These results suggested that individuals with AN view the compulsive nature of their behavior as central to the maintenance of their disorder, and as a significant barrier to recovery. The themes that emerged also showed parallels with the DSM-V criteria for SUDs, mapping onto the four groups of criteria (impaired control, social impairment, risky use of substance, pharmacological criteria). These results emphasize the need for further research to explore the possible parallels in behavioral and neural underpinnings of compulsivity in AN and SUDs, which may inform novel treatment avenues for AN.

Does anxiety improve during weight restoration in anorexia nervosa? A systematic review

Weight restoration is considered a principal outcome for treatment of Anorexia Nervosa (AN) due to the significant physiological disturbances resultant from acute states of malnutrition. Treatment outcomes for populations with AN are relatively poor, with increasing evidence suggesting that weight restoration alone is insufficient for long-term recovery. Research aimed at understanding the psychological sequaele of AN, in particular during weight restoration, nevertheless remain scarce. This systematic review aimed to evaluate existing research regarding anxiety symptoms during treatment for AN, and the relationship of anxiety symptomology and weight restoration. Twelve articles were identified from a systematic search of three electronic databases (PsycINFO, MEDLINE, and Web of Science), and were eligible for inclusion. Study methodology, results and quality were reviewed. Results regarding change in anxiety symptomology were inconsistent, though evidence did not support a relationship between anxiety change and weight restoration. Reasons for these inconsistencies and limitations of included studies were reviewed. Further research is warranted to elucidate the role of anxiety in AN and its implications for treatment and longer-term outcome.

Are Extremes of Consumption in Eating Disorders Related to an Altered Balance between Reward and Inhibition?

The primary defining characteristic of a diagnosis of an eating disorder (ED) is the "disturbance of eating or eating-related behavior that results in the altered consumption or absorption of food" (DSM V; American Psychiatric Association, 2013). There is a spectrum, ranging from those who severely restrict eating and become emaciated on one end to those who binge and overconsume, usually accompanied by some form of compensatory behaviors, on the other. How can we understand reasons for such extremes of food consummatory behaviors? Recent work on obesity and substance use disorders has identified behaviors and neural pathways that play a powerful role in human consummatory behaviors. That is, corticostriatal limbic and dorsal cognitive neural circuitry can make drugs and food rewarding, but also engage self-control mechanisms that may inhibit their use. Importantly, there is considerable evidence that alterations of these systems also occur in ED. This paper explores the hypothesis that an altered balance of reward and inhibition contributes to altered extremes of response to salient stimuli, such as food. We will review recent studies that show altered sensitivity to reward and punishment in ED, with evidence of altered activity in corticostriatal and insula processes with respect to monetary gains or losses, and tastes of palatable foods. We will also discuss evidence for a spectrum of extremes of inhibition and dysregulation behaviors in ED supported by studies suggesting that this is related to top-down self-control mechanisms. The lack of a mechanistic understanding of ED has thwarted efforts for evidence-based approaches to develop interventions. Understanding how ED behavior is encoded in neural circuits would provide a foundation for developing more specific and effective treatment approaches.

Temperament-based treatment for anorexia nervosa

Anorexia nervosa (AN) tends to be a chronic and deadly disorder with no proven treatments that reverse core symptoms in adults. New insight into neurobiological mechanisms that contribute to symptoms may support development of more effective interventions. We describe the development of a temperament-based treatment for AN on the basis of empirically supported models. It uses a systemized approach and takes into consideration an understanding of how neurobiological mechanisms are expressed through behaviour and personality and contribute to specific AN symptomatology. This model integrates the development of AN-focused constructive coping strategies with carer-focused strategies to manage temperament traits that contribute to AN symptomatology. This intervention is consistent with the recent Novel Interventions for Mental Disorders initiative mandating that treatment trials follow an experimental medicine approach by identifying underlying mechanisms that are directly targeted by the intervention to influence symptoms.

Emotional responses to images of food in adults with an eating disorder: a comparative study with healthy and clinical controls

Emotive responses to foods in people with eating disorders are incompletely understood in relation to whether the extent of emotional response is due to the eating disorder or non-specific emotional states. The aims of the present study were to investigate negative and positive emotive responses to food images in adults with an eating disorder, and to compare responses to a (i) healthy and a (ii) clinic (psychiatry) control group. Participants viewed 20 images (16 of foods previously found to evoke fear, disgust and happiness and 4 neutral images) at half-minute intervals and rated emotive responses on 3 visual analogue scales for each image. Participants with an eating disorder (n=26) were found to have significantly increased negative emotive (disgust and fear) responses and reduced positive (happiness) responses to the images compared to the 20 clinic and 61 healthy participants. Differences between groups remained significant when controlling for baseline levels of fear, disgust and happiness. Thus, the emotive responses to foods did not appear due to non-specific increases in anxiety or depression but rather was due to the presence of an eating disorder.

Hungry for reward: How can neuroscience inform the development of treatment for Anorexia Nervosa?

Dysfunctional reward from the pursuit of thinness presents a major challenge to recovery from Anorexia Nervosa (AN). We explore the neuroscientific basis of aberrant reward in AN, with the aim of generating novel hypotheses for translational investigation, and elucidate disease mechanisms to inform the development of targeted interventions. Relevant neuroimaging and behavioural studies are reviewed. These suggest that altered eating in AN may be a consequence of aberrant reward processing combined with exaggerated cognitive control. We consider evidence that such aberrant reward processing is reflected in the compulsive behaviours characterising AN, with substantial overlap in the neural circuits implicated in reward processing and compulsivity. Drawing on contemporary neuroscientific theories of substance dependence, processes underpinning the shift from the initially rewarding pursuit of thinness to extreme and compulsive weight control behaviours are discussed. It is suggested that in AN, weight loss behaviour begins as overtly rewarding, goal-directed and positively reinforced, but over time becomes habitual and increasingly negatively reinforced. Excessive habit formation is suggested as one underlying mechanism perpetuating compulsive behaviour. Ongoing research into the behavioural and neural basis of aberrant reward in AN is required to further elucidate mechanisms. We discuss clinical and transdiagnostic implications, and propose that future treatment innovation may benefit from the development of novel interventions targeting aberrant reward processing in AN.

Compulsivity in anorexia nervosa: a transdiagnostic concept

The compulsive nature of weight loss behaviors central to anorexia nervosa (AN), such as relentless self-starvation and over-exercise, has led to the suggestion of parallels between AN and other compulsive disorders such as obsessive-compulsive disorder (OCD) and addictions. There is a huge unmet need for effective treatments in AN, which has high rates of morbidity and the highest mortality rate of any psychiatric disorder, yet a grave paucity of effective treatments. Viewing compulsivity as a transdiagnostic concept, seen in various manifestations across disorders, may help delineate the mechanisms responsible for the persistence of AN, and aid treatment development. We explore models of compulsivity that suggest dysfunction in cortico-striatal circuitry underpins compulsive behavior, and consider evidence of aberrancies in this circuitry across disorders. Excessive habit formation is considered as a mechanism by which initially rewarding weight loss behavior in AN may become compulsive over time, and the complex balance between positive and negative reinforcement in this process is considered. The physiological effects of starvation in promoting compulsivity, positive reinforcement, and habit formation are also discussed. Further research in AN may benefit from a focus on processes potentially underlying the development of compulsivity, such as aberrant reward processing and habit formation. We discuss the implications of a transdiagnostic perspective on compulsivity, and how it may contribute to the development of novel treatments for AN.

Body checking and obsessive-compulsive symptoms in Brazilian outpatients with eating disorders

OBJECTIVE

Compare obsessive-compulsive symptoms in patients with anorexia nervosa (AN) and bulimia nervosa (BN), and assess the association of these symptoms and body checking in each of these groups of patients.

METHODS

Eighty-five female outpatients with eating disorders (ED) completed body checking and obsessive-compulsive questionnaires.

RESULTS

Body checking was more prevalent in the BN group. Among patients with AN, the highest mean body-checking scores were found in patients with somatic obsessions related to body areas and eating rituals (p = 0.003 and 0.018, respectively).

DISCUSSION

Patients with eating disorders are believed to be included in the obsessive-compulsive spectrum, and may experience intrusive thoughts about behavior. The results of our work suggest that obsessive symptoms and body checking should be further investigated and properly managed in patients with ED.

Confronting fear using exposure and response prevention for anorexia nervosa: A randomized controlled pilot study

OBJECTIVE

Anorexia nervosa (AN) is a severe illness with high rates of relapse. Exposure and Response Prevention for AN (AN-EXRP) is a new approach that specifically addresses maladaptive eating behavior by targeting eating-related fear and anxiety. The aim of this study was to evaluate AN-EXRP as an adjunctive strategy to improve eating behavior during weight restoration, at a pivotal moment when treatment goals shift toward relapse prevention.

METHOD

A randomized controlled trial was conducted to compare AN-EXRP with a comparison condition, Cognitive Remediation Therapy (CRT). Hospitalized patients with AN (n = 32) who had achieved weight restoration to a BMI > 18.5 kg/m(2) received 12 sessions of either AN-EXRP or CRT. Outcome was assessed by change in caloric intake in an objective assessment of eating behavior.

RESULTS

The average test meal caloric intake of participants who received AN-EXRP increased from 352 ± 263 kcal at baseline to 401 ± 215 kcal post-treatment, while that of participants who received CRT decreased from 501 ± 232 kcal at baseline to 424 ± 221 kcal post-treatment [t(28) = 2.5, p = .02]. Improvement in intake was significantly associated with improvement in eating-related anxiety (Spearman's ρ = 0.40, p = .03).

DISCUSSION

These data demonstrate that AN-EXRP, compared to a credible comparison intervention, is associated with better caloric intake in a laboratory meal over time in AN. Additional studies are required to determine whether incorporation of these techniques into a longer treatment program leads to enduring and clinically significant change.

Greater anterior insula activation during anticipation of food images in women recovered from anorexia nervosa versus controls

Individuals with anorexia nervosa (AN) restrict food consumption and become severely emaciated. Eating food, even thinking of eating food, is often associated with heightened anxiety. However, food cue anticipation in AN is poorly understood. Fourteen women recovered from AN and 12 matched healthy control women performed an anticipation task viewing images of food and object images during functional magnetic resonance imaging. Comparing anticipation of food versus object images between control women and recovered AN groups showed significant interaction only in the right ventral anterior insula, with greater activation in recovered AN anticipating food images. These data support the hypothesis of a disconnect between anticipating and experiencing food stimuli in recovered AN. Insula activation positively correlated with pleasantness ratings of palatable foods in control women, while no such relationship existed in recovered AN, which is further evidence of altered interoceptive function. Finally, these findings raise the possibility that enhanced anterior insula anticipatory response to food cues in recovered AN could contribute to exaggerated sensitivity and anxiety related to food and eating.

Psychological treatments for eating disorders

PURPOSE OF REVIEW

This review summarizes recent evidence on psychological treatments for eating disorders.

RECENT FINDINGS

Eating disorders are serious psychiatric conditions requiring evidence-based intervention. Treatments have been evaluated within each eating disorder diagnosis and across diagnoses. For adults with anorexia nervosa, no one specialist treatment has been shown to be superior. Cognitive behavioral therapy and interpersonal psychotherapy remain the most established treatments for bulimia nervosa and binge eating disorder, with stepped-care approaches showing promise and new behavioral treatments under study. Enhanced cognitive behavioral therapy has improved symptoms in adults and youth. Maudsley family-based therapy is the most established treatment for youth with anorexia nervosa and may be efficacious for youth with bulimia nervosa. Interpersonal psychotherapy for the prevention of excess weight gain may be efficacious for reducing loss of control eating and weight gain in overweight youth.

SUMMARY

Significant advances in treatments have been made, including evaluation of long-term outcomes, novel approaches, and tailored extension for specific patient profiles. However, widespread access to effective eating disorder treatments remains limited. Increasing the potency and expanding the implementation of psychological treatments beyond research settings into clinical practice has strong potential to increase access to care, thereby reducing the burden of eating disorders.

Emerging psychological treatments in the field of eating disorders

Few treatments for eating disorders have established a base of empirical support, and those that have are still limited by high dropout rates and low abstinence rates. Thus, there is a critical need for innovative eating disorder treatments to fill this gap. The past decade has seen a surge in the development of novel treatments that address eating pathology. This review provides an overview of the emerging psychological treatments for eating disorders, including descriptions of the therapeutic rationales, treatment techniques, and research support. The review will cover face-to-face interventions that are provided in the context of individual or group psychotherapy. Treatments included in this review were organized into the following six categories based on their underlying therapeutic rationales: (1) cognition-focused approaches, (2) emotion regulation approaches, (3) exposure-based approaches, (4) motivational enhancement, (5) integrative approaches, and (6) family- and couple-based interventions.

Using an OCD formulation in the treatment of anorexia nervosa: a useful way to understand the illness?

Anorexia nervosa (AN) and obsessive compulsive disorder (OCD) have been shown to have a number of commonalities, such as genetics, neurobiology, and symptoms. Approaches to treatment of AN have recently been described that take such findings into account, extending interventions recommended for obsessive compulsive and anxiety disorders to AN. The current paper aims to outline a formulation model of AN in adults, derived from the literature on OCD, and introduce this topic as a fruitful area to build on existing treatment techniques, and to prompt further discussion of such techniques. A formulation model is described, followed by a discussion of how this might be applied to AN, using examples from clinical practice. Potential benefits and difficulties are discussed. A formulation model is suggested that can easily be adapted to AN, complementing existing models in eating disorders.

A system of evidenced-based techniques and collaborative clinical interventions with a chronically ill patient

Although evidence-based treatments (EBTs) exist for both bulimia nervosa and binge eating disorder, there is far less evidence underpinning the treatment of anorexia nervosa (AN). Furthermore, there is no clearly defined standardized approach to patients who have not responded to treatment over an extended period of time. Chronic eating disorder patients in particular might need long-term engagement with treatment providers offering a wide range of interventions. This case study highlights how an experienced private practitioner systematically employed a variety of EBT techniques for a patient with a severe, long-term eating disorder and its comorbidities, within a model of attachment and collaboration. The practice of utilizing a wide variety of EBT techniques in a systematic manner guided by clinical expertise and supported by a therapy relationship of collaboration and attachment may prove to be a fruitful avenue for future research.

Caloric restriction enhances fear extinction learning in mice

Fear extinction learning, the ability to reassess a learned cue of danger as safe when it no longer predicts aversive events, is often dysregulated in anxiety disorders. Selective serotonin reuptake inhibitors (SSRI's) enhance neural plasticity and their ability to enhance fear extinction learning may explain their anxiolytic properties. Caloric restriction (CR) has SSRI-like effects on neural plasticity and anxiety-related behavior. We implemented CR in mice to determine its effects on conditioned-fear responses. Wild type and serotonin transporter (SERT) knockout mice underwent CR for 7 days leading to significant weight loss. Mice were then tested for cued fear learning and anxiety-related behavior. CR markedly enhanced fear extinction learning and its retention in adolescent female mice, and adults of both sexes. These effects of CR were absent in SERT knockout mice. Moreover, CR phenocopied behavioral and molecular effects of chronic fluoxetine, but there was no additive effect of CR in fluoxetine-treated mice. These results demonstrate that CR enhances fear extinction learning through a SERT-dependent mechanism. These results may have implications for eating disorders such as anorexia nervosa (AN), in which there is a high prevalence of anxiety before the onset of dietary restriction and support proposals that in AN, CR is a motivated effort to control dysregulated fear responses and elevated anxiety.

Does a shared neurobiology for foods and drugs of abuse contribute to extremes of food ingestion in anorexia and bulimia nervosa?

Is starvation in anorexia nervosa (AN) or overeating in bulimia nervosa (BN) a form of addiction? Alternatively, why are individuals with BN more vulnerable and individuals with AN protected from substance abuse? Such questions have been generated by recent studies suggesting that there are overlapping neural circuits for foods and drugs of abuse. To determine whether a shared neurobiology contributes to eating disorders and substance abuse, this review focused on imaging studies that investigated response to tastes of food and tasks designed to characterize reward and behavioral inhibition in AN and BN. BN and those with substance abuse disorders may share dopamine D2 receptor-related vulnerabilities, and opposite findings may contribute to "protection" from substance abuse in AN. Moreover, imaging studies provide insights into executive corticostriatal processes related to extraordinary inhibition and self-control in AN and diminished inhibitory self-control in BN that may influence the rewarding aspect of palatable foods and likely other consummatory behaviors. AN and BN tend to have premorbid traits, such as perfectionism and anxiety that make them vulnerable to using extremes of food ingestion, which serve to reduce negative mood states. Dysregulation within and/or between limbic and executive corticostriatal circuits contributes to such symptoms. Limited data support the hypothesis that reward and inhibitory processes may contribute to symptoms in eating disorders and addictive disorders, but little is known about the molecular biology of such mechanisms in terms of shared or independent processes.

The relationship between anorexia nervosa and body dysmorphic disorder

Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are severe body image disorders that highly impair individuals in their daily functioning. They are discrete but overlapping nosological entities. In this review, we examine similarities between AN and BDD with regard to clinical, personality and demographic aspects, such as comorbidity, phenomenology, and treatment outcome. The review suggests that the two disorders are highly comorbid, and show similar ages of onset, illness trajectories, and comparable clinical and personality characteristics. However, important differences emerge in their responsiveness to psychosocial and psychopharmacological treatment, which are discussed. Clinical implications of these findings are summarized and directions for future research are delineated, with a focus on how current treatment components from each disorder may inform new interventions for both disorders.

Nothing tastes as good as skinny feels: the neurobiology of anorexia nervosa

Individuals with anorexia nervosa (AN) engage in relentless restrictive eating and often become severely emaciated. Because there are no proven treatments, AN has high rates of relapse, chronicity, and death. Those with AN tend to have childhood temperament and personality traits, such as anxiety, obsessions, and perfectionism, which may reflect neurobiological risk factors for developing AN. Restricted eating may be a means of reducing negative mood caused by skewed interactions between serotonin aversive or inhibitory and dopamine reward systems. Brain imaging studies suggest that altered eating is a consequence of dysregulated reward and/or awareness of homeostatic needs, perhaps related to enhanced executive ability to inhibit incentive motivational drives. An understanding of the neurobiology of this disorder is likely to be important for developing more effective treatments.

Treatment of obsessive-compulsive disorder complicated by comorbid eating disorders

PURPOSE

Eating disorders and obsessive-compulsive disorder (OCD) commonly co-occur, but there is little data for how to treat these complex cases. To address this gap, we examined the naturalistic outcome of 56 patients with both disorders, who received a multimodal treatment program designed to address both problems simultaneously.

METHODS

A residential treatment program developed a cognitive-behavioral approach for patients with both OCD and an eating disorder by integrating exposure and response prevention (ERP) treatment for OCD with ERP strategies targeting eating pathology. Patients also received a supervised eating plan, medication management, and social support. At admission and discharge, patients completed validated measures of OCD severity (the Yale-Brown Obsessive-Compulsive Scale--Self Report [Y-BOCS-SR]), eating disorder severity (the Eating Disorders Examination-Questionnaire), and depressive severity (the Beck Depression Inventory II [BDI-II]). Body mass index (BMI) was also measured. Paired-sample t-tests examined change on these measures.

MAIN RESULTS

Between 2006 and 2011, 56 individuals completed all study measures at admission and discharge. Mean length of stay was 57 days (SD = 27). Most (89%) were on psychiatric medications. Significant decreases were observed in OCD severity, eating disorder severity, and depression. Those with bulimia nervosa showed more improvement than those with anorexia nervosa. BMI significantly increased, primarily among those underweight at admission.

CONCLUSION

Simultaneous treatment of OCD and eating disorders using a multimodal approach that emphasizes ERP techniques for both OCD and eating disorders can be an effective treatment strategy for these complex cases.