Treatment outcomes for eating disorders in Sweden: data from the national quality registry

Staging models in eating disorders: A systematic scoping review of the literature

Eating Disorders (ED) are characterized by low remission rates, treatment drop-out, and residual symptoms. To improve assessment and treatment of ED, the staging approach has been proposed. This systematic scoping review is aimed at mapping the existing staging models that explicitly propose stages of the progression of ED. A systematic search of PubMed, PsycINFO, Scopus was conducted with the terms staging, anorexia nervosa, bulimia nervosa, binge-eating disorders, eating disorders. Eleven studies met inclusion criteria presenting nine ED staging models, mostly for anorexia nervosa. Three were empirically tested, one of which was through an objective measure specifically developed to differentiate between stages. Most staging models featured early stages in which the exacerbation of EDs unfolds and acute phases are followed by chronic stages. Intermediate stages were not limited to acute stages, but also residual phases, remission, relapse, and recovery. The criteria for stage differentiation encompassed behavioral, psychological, cognitive, and physical features including body mass index and illness duration. One study recommended stage-oriented interventions. The current review underscores the need to empirically test the available staging models and to develop and test new proposals of staging models for other ED populations. The inclusion of criteria based on medical features and biomarkers is recommended. Staging models can potentially guide assessment and interventions in daily clinical settings.

The Follow-Up of Eating Disorders from Adolescence to Early Adulthood: A Systematic Review

Eating disorders (EDs) are common among children and adolescents and are characterized by excessive concerns for physical appearance, distorted body image, and fear of gaining weight. The purpose of this review is to evaluate the follow-up of EDs from adolescence to adulthood, analyzing persistence, relapses, and associated comorbidities. We searched scientific articles in PubMed, PsycInfo, Scopus, and Embase through two research strings, one for quantitative outcomes (recovery/persistence, relapse, and remission) and one for the other outcomes (psychiatric and medical comorbidities, substance use, and social-relational complications). From a total of 8043 retrieved articles, we selected 503 papers after exclusion of duplicates and title/abstract screening. After a full-text evaluation, we included 16 studies eligible for this review. We performed a meta-analysis describing the quantitative results, and we created a narrative synthesis for the qualitative outcomes. Results: Our results confirm that EDs can persist in early adulthood in 40.7% of cases with a relapse percentage of 24.5%. Individuals with an ED more frequently present with an empathy deficit and comorbid anxiety and depressive disorders. EDs are chronic and complex disorders, more frequent in females. In most cases, EDs reduce the autonomy of individuals who present many difficulties in affirming their independence from parental family.

A community-based feasibility randomized controlled study to test food-specific inhibitory control training in people with disinhibited eating during COVID-19 in Italy

PURPOSE

The aim of this study was to expand the evidence on the feasibility and impact of food-specific inhibitory control training in a community sample of people with disinhibited eating.

METHODS

Recruitment and data collection were conducted during the COVID-19 outbreak, in Italy. Ninety-four adult individuals with disinhibited eating were randomised to one of two conditions: App-based food-specific inhibitory control training or waiting list. Participants were assessed at baseline, end of intervention (2 weeks following baseline) and follow-up (one week later). The assessment measures included questionnaires about eating behaviour and mood.

RESULTS

Seventy-three percent of the sample reported a diagnosis of binge eating disorder, and 20.4% a diagnosis of bulimia nervosa. Retention rates were 77% and 86% for the food-specific inhibitory control training and the waiting list conditions, respectively. Almost half of the participants allocated to the training condition completed the "recommended" dose of training (i.e., 10 or more sessions). Those in the training condition reported lower levels of wanting for high-energy dense foods (p < 0.05), a trend for lower levels of perceived hunger (p = 0.07), and lower levels of depression (p < 0.05). Binge eating symptoms, disinhibition, wanting for high-energy dense foods, stress and anxiety were significantly lower at end of intervention, compared to baseline (p < .05).

CONCLUSION

Findings corroborated the feasibility of food-specific inhibitory control training, and its impact on high-energy dense foods liking. The study expands the evidence base for food-specific inhibitory control training by highlighting its impact on perceived hunger and depression. The mechanisms underlying these effects remain to be clarified.

LEVEL OF EVIDENCE

Level I, Evidence obtained from at least one properly designed randomized controlled trials; systematic reviews and meta-analyses; experimental studies.

Are the Effects of Malnutrition on the Gut Microbiota–Brain Axis the Core Pathologies of Anorexia Nervosa?

Anorexia nervosa (AN) is a disabling, costly, and potentially deadly illness. Treatment failure and relapse after treatment are common. Several studies have indicated the involvement of the gut microbiota–brain (GMB) axis. This narrative review hypothesizes that AN is driven by malnutrition-induced alterations in the GMB axis in susceptible individuals. According to this hypothesis, initial weight loss can voluntarily occur through dieting or be caused by somatic or psychiatric diseases. Malnutrition-induced alterations in gut microbiota may increase the sensitivity to anxiety-inducing gastrointestinal hormones released during meals, one of which is cholecystokinin (CCK). The experimental injection of a high dose of its CCK-4 fragment in healthy individuals induces panic attacks, probably via the stimulation of CCK receptors in the brain. Such meal-related anxiety attacks may take part in developing the clinical picture of AN. Malnutrition may also cause increased effects from appetite-reducing hormones that also seem to have roles in AN development and maintenance. The scientific background, including clinical, microbiological, and biochemical factors, of AN is discussed. A novel model for AN development and maintenance in accordance with this hypothesis is presented. Suggestions for future research are also provided.

The Universal Eating Monitor (UEM): objective assessment of food intake behavior in the laboratory setting

The Universal Eating Monitor was a term used to describe a device used in a laboratory setting that enabled investigators to measure, with the same instrument, the rate of eating either solids or liquids, hence the term “universal”. It consisted of an electronic balance placed in a false panel under a table cloth on which could be placed a food reservoir that contained either solid or liquefied food. The device was created in order to determine whether rates of eating differed in pattern between solid and liquid foods. An acceptable mixture of foods of identical composition that could be served as either solid or blended as a liquid was used to test the hypothesis that eating rate and intake were affected by physical composition. A best-fitting mathematical function (intake was quadratic function of time, with coefficients varying among foods used and experimental conditions), quantified intake rates. The device was used to test a variety of mechanisms underlying food intake control. Eating rates were linear when solid foods were used, but negatively accelerated with liquids. Overall, intake did not differ between solid and liquefied food of identical composition. Satiation on a calorie for calorie basis was different among foods, but physical composition interacted with energy density. Hormones and gastric distension were strong influences on food intake and rate of eating. Individuals with bulimia nervosa and binge eating disorder ate more than individuals without these disturbances. Intake in social and individual contexts was identical, but the rate of eating was slower when two individuals dined together. The eating monitor has been a useful instrument for elucidating controls of food intake and describing eating pathology.

Treating Eating: A Dynamical Systems Model of Eating Disorders

Mainstream forms of psychiatric talk therapy and cognitive behavioral therapy (CBT) do not reliably generate lasting recovery for eating disorders. We discuss widespread assumptions regarding the nature of eating disorders as fundamentally psychological disorders and highlight the problems that underlie these notions, as well as related practical problems in the implementation of mainstream treatments. We then offer a theoretical and practical alternative: a dynamical systems model of eating disorders in which behavioral interventions are foregrounded as powerful mediators between psychological and physical states. We go on to present empirical evidence for behavioral modification specifically of eating speed in the treatment of eating disorders, and a hypothesis accounting for the etiology and progression, as well as the effective treatment, of the full spectrum of eating problems. A dynamical systems approach mandates that in any dietary and lifestyle change as profound as recovery from an eating disorder, acknowledgment must be made of the full range of pragmatic (psychological, cultural, social, etc.) factors involved. However, normalizing eating speed may be necessary if not sufficient for the development of a reliable treatment for the full spectrum of eating disorders, in its role as a mediator in the complex feedback loops that connect the biology and the psychology with the behaviors of eating.

Temperature but not leptin prevents semi-starvation induced hyperactivity in rats: implications for anorexia nervosa treatment

The hypothesis linking hyperactivity with weight loss associated hypoleptinemia in anorexia nervosa gained momentum after a study showing that leptin suppressed semi-starvation induced hyperactivity in rats. Alternatively, ambient temperature is a key modulating factor of activity in semi-starved rats. The aim of the study is to compare the efficacy of leptin with increased ambient temperature in the prevention of hyperactivity in semi-starved rats. 74 Sprague-Dawley male rats were employed in two experiments with the difference residing in the length of baseline. After an extended (28 days), or shorter (14 days) baseline with free access to food and the running wheel, housed at 21 °C, animals were either ad-lib feed or food restricted (60% of food ingested during previous week) and infused with same amount of leptin at 21 °C, 25 °C, or vehicle at 21 °C, 25 °C and 32 °C for a week. Animals housed at 32 °C significantly reduced wheel running and weight loss during food restriction while animals given leptin did not yield no differences in activity or weight loss. Moreover, unlike animals housed at 32 °C, body temperature of leptin infused animals housed at 21 °C was significantly reduced during food restriction. Furthermore, leptin treated rats without a preceding stable pattern of activity displayed a severe dysregulation of circadian rhythm in activity and a collapse of body temperature. Housing temperature plays a more critical role than leptin in the regulation of semi-starvation induced hyperactivity in rats, which may be of relevance for the management of hyperactivity in anorexia nervosa.

Verifying Feighner's Hypothesis; Anorexia Nervosa Is Not a Psychiatric Disorder

Mental causation takes explanatory priority over evolutionary biology in most accounts of eating disorders. The evolutionary threat of starvation has produced a brain that assists us in the search for food and mental change emerges as a consequence. The major mental causation hypothesis: anxiety causes eating disorders, has been extensively tested and falsified. The subsidiary hypothesis: anxiety and eating disorders are caused by the same genotype, generates inconsistent results because the phenotypes are not traits, but vary along dimensions. Challenging the mental causation hypothesis in Feighner et al. (1972) noted that anorexic patients are physically hyperactive, hoarding for food, and they are rewarded for maintaining a low body weight. In 1996, Feighner's hypothesis was formalized, relating the patients' behavioral phenotype to the brain mechanisms of reward and attention (Bergh and Södersten, 1996), and in 2002, the hypothesis was clinically verified by training patients how to eat normally, thus improving outcomes (Bergh et al., 2002). Seventeen years later we provide evidence supporting Feighner's hypothesis by demonstrating that in 2012, 20 out of 37 patients who were referred by a psychiatrist, had a psychiatric diagnosis that differed from the diagnosis indicated by the SCID-I. Out of the 174 patients who were admitted in 2012, most through self-referral, there was significant disagreement between the outcomes of the SCID-I interview and the patient's subjective experience of a psychiatric problem in 110 of the cases. In addition, 358 anorexic patients treated to remission scored high on the Comprehensive Psychopathological Rating Scale, but an item response analysis indicated one (unknown) underlying dimension, rather than the three dimensions the scale can dissociate in patients with psychiatric disorders. These results indicate that psychiatric diagnoses, which are reliable and valid in patients with psychiatric disorders, are less well suited for patients with anorexia. The results are in accord with the hypothesis of the present Research Topic, that eating disorders are not always caused by disturbed psychological processes, and support the alternative, clinically relevant hypothesis that the behavioral phenotype of the patients should be addressed directly.

Eating Behavior and the Evolutionary Perspective on Anorexia Nervosa

On the standard perspective, anorexia nervosa and other eating disorders are caused by genetically determined, neurochemically mediated mental illnesses. Standard treatment, cognitive behavioral therapy (CBT), targets cognitive processes thought to maintain the disorders. Effective neurochemically based treatments are not available and the rate of remission is ≤25% 1 year after CBT, with unknown outcomes in the long-term. With starvation as the major threat in biological history, the evolutionary perspective focuses on foraging for food and eating behavior. A neural network, including hypothalamic arcuate peptide-neurons, brainstem serotonin- and dopamine-neurons and their prefrontal cortical projections, mediates (rather than controls) the behavioral adaptations to variations in food availability; activation of the network is associated with opposing behavioral outcomes depending upon external variations. In the clinic, the control of eating behavior is therefore outsourced to a machine that provides feedback on how to eat. Hundreds of eating disorders patients have recovered by practicing eating; the rate of remission is 75% in on average 1 year of treatment, the rate of relapse is 10% over 5 years of follow-up and no patient has died. A two-parameter asymptotic exponential growth curve modeled the eating behavior of 17 healthy women but not that of 17 women with anorexia nervosa. When in remission, the eating behavior of the anorexic women approached that of the healthy women. It is suggested that the treatment of eating disorders should focus on eating behavior.