The promise of neurobiological research in anorexia nervosa

EEG Spatial-temporal Dynamics of Resting-state Activity in Young Women with Anorexia Nervosa: Preliminary Evidence

The aim of this study was to provide preliminary evidence on temporal dynamics of resting-state brain networks in youth with anorexia nervosa (AN) using electroencephalography (EEG). Resting-state EEG data were collected in 18 young women with AN and 18 healthy controls (HC). Between-group differences in brain networks were assessed using microstates analyses. Five microstates were identified across all subjects (A, B, C, D, E). Using a single set of maps representative of the whole dataset, group differences were identified for microstates A, C, and E. A common-for-all template revealed a relatively high degree of consistency in results for reduced time coverage of microstate C, but also an increased presence of microstate class E. AN and HC had different microstate transition probabilities, largely involving microstate A. Using LORETA, for microstate D, we found that those with AN had augmented activations in the left frontal inferior operculum, left insula, and bilateral paracentral lobule, compared with HC. For microstate E, AN had augmented activations in the para-hippocampal gyrus, caudate, pallidum, cerebellum, and cerebellar vermis. Our findings suggest altered microstates in young women with AN associated with integration of sensory and bodily signals, monitoring of internal/external mental states, and self-referential processes. Future research should examine how EEG-derived microstates could be applied to develop diagnostic and prognostic models of AN.

Childhood onset exercise addiction or atypical anorexia nervosa during Covid-19: case report

BACKGROUND

Childhood-onset Anorexia Nervosa (AN) is recognised to be atypical in presentation, both in terms of extent and nature of eating pathology, exercise and compensatory behaviours with many falling short of full diagnostic criteria. Failure to consider an eating disorder diagnosis in youth who present with extreme weight loss may have serious immediate and long term implications. However, failure to consider other non-organic causes of weight loss may be equally detrimental to the child's health.

CASE PRESENTATION

This case reports on the acute presentation of a 12-year old boy, who presented to hospital in a severely malnourished state eight weeks into lockdown. To compensate for Covid-19 induced restrictions on sporting activity, this boy had followed a self-imposed daily schedule of arduous exercise, without increasing his nutritional intake. This report examines the clinical features suggestive of AN and other differential diagnosis. A discussion on the specific diagnostic differential of exercise addiction and challenges faced by youth during Covid-19 restrictions are presented.

CONCLUSION

Accepting that AN may present atypically in pre-pubertal youth, it is important that clinicians maintain an open mind in youth presenting without goal directed weight loss. Although weight loss was significant in this case, it was due to an excessive exercise regime. This may have commenced as a coping strategy in response to Covid-19 restrictions but subsequently became excessive and impairing in nature. The collateral damage of Covid-19 mandated restrictions, aimed at containing the spread of the virus, are evident in this case. Clinicians need to be alert to potentially maladaptive coping strategies and unusual or altered pathways of presentation, especially in younger children during these challenging times.

Developments in the psychological treatment of anorexia nervosa and their implications for daily practice

PURPOSE OF REVIEW

Our aim is to give an overview of the recent literature on psychological treatment for young adults and adults with anorexia nervosa and to discuss the implications of the findings for clinical practice.

RECENT FINDINGS

Three systematic reviews and meta-analyses have recently been published on psychological treatments for anorexia nervosa. Treatment outcomes are still modest and mainly focus on weight outcome, although outcomes for eating disorder disease and quality of life have also been reported. Adhering to a treatment protocol might lead to faster and better results.

SUMMARY

For children and adolescents with anorexia nervosa, the major guidelines recommend a family-based treatment. The treatments of choice for young adults and adults with anorexia nervosa are the Maudsley Anorexia Nervosa Treatment for Adults (MANTRA), Cognitive Behaviour Therapy-Enhanced (CBT-E) and Specialist Supportive Clinical Management (SSCM), but none of these treatments seem to be superior. In search of other ways to improve outcome, shared decision making may be a way to help patients become more involved in their treatment, enhance their motivation and consequently improve the outcome.

Moving towards specificity: A systematic review of cue features associated with reward and punishment in anorexia nervosa

Models of anorexia nervosa (AN) posit that symptoms are maintained through deficient reward and enhanced punishment processing. However, theoretical and empirical inconsistencies highlight the need for a more nuanced conceptualization of this literature. Our goal was to comprehensively review the research on reward and punishment responding in AN from a cue-specific lens to determine which stimuli evoke or discourage reward and punishment responses in this population, and, ultimately, what properties these rewarding and punishing cues might share. A systematic review interrogating reward and punishment responses to specific cues yielded articles (n = 92) that examined responses to disorder relevant (e.g., food) and irrelevant (e.g., money) stimuli across self-report, behavioral, and biological indices. Overall, in most studies individuals with AN exhibited aversive responses to cues signaling higher body weights, social contexts, and monetary losses, and appetitive responses to cues for weight loss behaviors and thinness. Findings were more mixed on responses to palatable food and monetary gains. Results highlight that reward and punishment responding in AN are context specific and may be affected by varied stimulus qualities (e.g., predictability, controllability, delay, effort). Increasing specificity in future research on reward and punishment mechanisms in AN will better inform development of precisely-targeted interventions.

Strengthened Default Mode Network Activation During Delay Discounting in Adolescents with Anorexia Nervosa After Partial Weight Restoration: A Longitudinal fMRI Study

The capacity of patients with anorexia nervosa (AN) to resist food-based rewards is often assumed to reflect excessive self-control. Previous cross-sectional functional magnetic resonance imaging (fMRI) studies utilizing the delay discounting (DD) paradigm, an index of impulsivity and self-control, suggested altered neural efficiency of decision-making in acutely underweight patients (acAN) and a relative normalization in long-term, weight-recovered individuals with a history of AN (recAN). The current longitudinal study tested for changes in functional magnetic resonance imaging (fMRI) activation during DD associated with intensive weight restoration treatment. A predominately adolescent cohort of 22 female acAN patients (mean age—15.5 years) performed an established DD paradigm during fMRI at the beginning of hospitalization and again after partial weight restoration (≥12% body mass index (BMI) increase). Analyses investigated longitudinal changes in both reward valuation and executive decision-making processes. Additional exploratory analyses included comparisons with data acquired in aged-matched healthy controls (HC) as well as probes of functional connectivity between empirically identified nodes of the “task-positive” frontoparietal control network (FPN) and “task-negative” default-mode network (DMN). While treatment was not associated with changes in behavioral DD parameters or activation, specific to reward processing, deactivation of the DMN during decision-making was significantly less pronounced following partial weight restoration. Strengthened DMN activation during DD might reflect a relative relaxation of cognitive overcontrol or improved self-referential, decision-making. Together, our findings present further evidence that aberrant decision-making in AN might be remediable by treatment and, therefore, might constitute an acute effect rather than a core trait variable of the disorder.

Neuroscience of Adolescent Anorexia Nervosa: Implications for Family-Based Treatment (FBT)

Over the past 20 years significant progress has been made to elucidate some of the neurobiological underpinnings of the development and maintenance of anorexia nervosa and their possible implications for treatment. There is increasing evidence supporting the notion that anorexia nervosa shares neurobehavioral patterns with anxiety disorders and involves reward processing aberrations and habit formation. There is consensus for the need of early intervention to ameliorate the effects of starvation on the adolescent brain and the effects of illness duration on neurodevelopment. Family-based treatment (FBT) is the first line evidence-based treatment for adolescents with anorexia nervosa achieving sustainable full remission rates of over 40%. FBT has an agnostic treatment approach and its mechanisms of change have until now not been fully understood. To help fill this gap in theoretical understanding, this paper will provide a review of the treatment model of FBT through a neuroscientific lens. It argues that FBT is well designed to address the implications of current key findings of the neuroscience of anorexia nervosa and that it is also well aligned with the current understanding of neuroscience principles underpinning therapeutic change. The paper supports the perspective that FBT utilizes principles of parent facilitated exposure response prevention. It concludes that an integration of a neuroscience perspective to the provision of FBT will assist the clinician in their practice of FBT.