The Neuropsychological Profile of Severe and Enduring Anorexia Nervosa: A Systematic Review

Does hypoleptinemia trigger entrapment in anorexia nervosa? Etiological and clinical considerations

Based on the recent observation that human recombinant leptin (r-Met-hu-leptin; metreleptin) may induce a profound alleviation of the complex symptomatology of patients with anorexia nervosa (AN), we examine the implications for our conceptualisation of this eating disorder. Hypoleptinemia as a core endocrine feature of AN serves as a central and peripheral trigger of tissue-specific adaptations to starvation. In this narrative review, we argue that leptin deficiency may explain many of the puzzling features of this eating disorder. Weight loss can be viewed as a two-step process, with only the second step entailing hypoleptinemia and thereby the entrapment characteristic of AN. We discuss the central and peripheral distribution of leptin receptors and consider possible functional implications of hypoleptinemia. We contrast the slow psychological recovery of patients with AN and of people who experienced starvation upon weight recovery with the rapid onset of improvements upon off-label metreleptin treatment. Characteristics of the sex and age dependent secretion of leptin may contribute to the elevated vulnerability of young females to develop AN.

Inclusion of the severe and enduring anorexia nervosa phenotype in genetics research: a scoping review

BACKGROUND

Anorexia nervosa has one of the highest mortality rates of all mental illnesses. For those who survive, less than 70% fully recover, with many going on to develop a more severe and enduring phenotype. Research now suggests that genetics plays a role in the development and persistence of anorexia nervosa. Inclusion of participants with more severe and enduring illness in genetics studies of anorexia nervosa is critical.

OBJECTIVE

The primary goal of this review was to assess the inclusion of participants meeting the criteria for the severe enduring anorexia nervosa phenotype in genetics research by (1) identifying the most widely used defining criteria for severe enduring anorexia nervosa and (2) performing a review of the genetics literature to assess the inclusion of participants meeting the identified criteria.

METHODS

Searches of the genetics literature from 2012 to 2023 were performed in the PubMed, PsycINFO, and Web of Science databases. Publications were selected per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The criteria used to define the severe and enduring anorexia nervosa phenotype were derived by how often they were used in the literature since 2017. The publications identified through the literature search were then assessed for inclusion of participants meeting these criteria.

RESULTS

most prevalent criteria used to define severe enduring anorexia nervosa in the literature were an illness duration of ≥ 7 years, lack of positive response to at least two previous evidence-based treatments, a body mass index meeting the Diagnostic and Statistical Manual of Mental Disorders-5 for extreme anorexia nervosa, and an assessment of psychological and/or behavioral severity indicating a significant impact on quality of life. There was a lack of consistent identification and inclusion of those meeting the criteria for severe enduring anorexia nervosa in the genetics literature.

DISCUSSION

This lack of consistent identification and inclusion of patients with severe enduring anorexia nervosa in genetics research has the potential to hamper the isolation of risk loci and the development of new, more effective treatment options for patients with anorexia nervosa.

Cognitive performance in hospitalized patients with severe or extreme anorexia nervosa

PURPOSE

Severe malnourishment may reduce cognitive performance in anorexia nervosa (AN). We studied cognitive functioning during intensive nutritional and medical stabilization in patients with severe or extreme AN and investigated associations between weight gain and cognitive improvement.

METHODS

A few days after admission to a specialized hospital unit, 33 patients with severe or extreme AN, aged 16-42 years, completed assessments of memory, cognitive flexibility, processing speed, and attention. Mean hospitalization was 6 weeks. Patients completed the same assessments at discharge (n = 22) following somatic stabilization and follow-up up to 6 months after discharge (n = 18).

RESULTS

The patients displayed normal cognitive performance at admission compared to normative data. During nutritional stabilization, body weight increased (mean: 11.3%; range 2.6-22.2%) and memory, attention, and processing speed improved (p values: ≤ 0.0002). No relationship between weight gain and cognitive improvement was observed at discharge or follow-up.

CONCLUSIONS

Cognitive performance at hospital admission was normal in patients with severe or extreme AN and improved during treatment although without association to weight gain. Based on these results, which are in line with previous studies, patients with severe or extreme AN need not be excluded from cognitively demanding tasks, possibly including psychotherapy. As patients may have other symptoms that interfere with psychotherapy, future research could investigate cognitive functioning in everyday life in patients with severe AN.

TRIAL REGISTRATION NUMBER

The study is registered at clinicaltrials.gov (NCT02502617).

LEVEL OF EVIDENCE

Level III, cohort study.

Cognitive Flexibility in Hospitalized Patients with Severe or Extreme Anorexia Nervosa: A Case-Control Study

OBJECTIVE

To investigate whether cognitive inflexibility could be identified using the Wisconsin Card Sorting Test (WCST) in patients with severe and extreme anorexia nervosa (AN) compared to healthy control participants (HCs).

METHOD

We used the WCST to assess 34 patients with AN (mean age: 25.9 years, mean body mass index (BMI): 13.2 kg/m²) 3-7 days after admission to a specialized nutrition unit and 34 HCs. The Beck Depression Inventory II and the Eating Disorder Inventory 3 were distributed.

RESULTS

The patients displayed more perseveration than HCs controlled for age and years of education, with moderate effect sizes (perseverative responses (%): adjusted difference = -7.74, 95% CI: -14.29-(-1.20), p-value: 0.021; perseverative errors (%): adjusted difference = -6.01, 95% CI: -11.06-(-0.96), p-value: 0.020). There were no significant relationships between perseveration and depression, eating disorder symptoms, illness duration, or BMI.

DISCUSSION

Patients with severe and extreme AN demonstrated lower cognitive flexibility compared to HCs. Performance was not related to psychopathology or BMI. Patients with severe and extreme anorexia nervosa may not differ from less severe patients in cognitive flexibility performance. As this study exclusively focused on patients suffering from severe and extreme AN, potential correlations might be masked by a floor effect.

Emergency room presentations of people with anorexia nervosa

People with anorexia nervosa (AN) tend to shy away from engaging in typical primary care provider relationships in order to avoid detection. Therefore, they may seek care for their medical concerns through a local emergency department (ED). Inherently, AN is associated with a litany of medical complications, which become more prevalent as the severity of their eating disorder increases. Notwithstanding the typical young age at the onset of AN, no body system is immune to these medical complications. Thus, ED providers may need to pursue a medical diagnosis in order to explain presenting symptoms in people with AN. In addition to the medical issues, AN is also a serious mental illness with high mortality rates, including deaths by suicide. Therefore, ED providers also need to be familiar with relevant mental health issues for these people.

MC, Bidika E. A Clinical Overview of Anorexia Nervosa and Overcoming Treatment Resistance

Anorexia nervosa (AN) is a type of eating disorder that has been increasing in incidence and has been encountered more commonly by physicians in their daily practice. Both environmental and genetic risk factors paired along with a more susceptible neurobiology are at play in the emerging resistance to treatment in AN. Preoccupations with intense fear of weight gain, dietary restrictions, excessive exercise, and how the individual is perceived by society mixed with underlying psychopathology all further add to the issue. Many patients who fall into this cycle of obsessive and restrictive patterns refuse to get treatment. As clinicians, it is essential we recognize the early signs of both eating disorders during the initial primary care appointments.

To review the literature on the etiology of AN, possible misdiagnosis leading to inappropriate management of this condition, and understand the treatment-resistant AN and its management. Additionally, it will explore possible reasons that contribute to the resistance to treatment, the underlying psychopathology of anorexics, its genetic predisposition, psychiatric comorbidities, identification of the early signs and symptoms, and timely prevention.

Early recognition by a physician includes a thorough history and physical examination, pertinent laboratory, and electrolyte studies, and identifying comorbid psychiatric conditions. The treatment of AN is intricate and requires a holistic approach. Treatment includes multiple modalities such as nutritional rehabilitation and psychosocial and pharmacological therapies. An interdisciplinary team of medical professionals for managing chronic AN is recommended.

Terminal anorexia nervosa is a dangerous term: it cannot, and should not, be defined

A recent article (JED 10:23, 2022) proposed defining terminal anorexia to improve access to palliative and hospice care, and to medical aid in dying for a minority of patients with severe and enduring anorexia nervosa (SE-AN). The authors presented three cases and, for two, the first author participated in their death. Anorexia nervosa is a treatable psychiatric condition for which recovery may be uncertain. We are greatly concerned however regarding implications of applying the label "terminal" to anorexia nervosa and the risk it will lead to unjustified deaths in individuals whose mental illness impairs their capacity to make a reasoned treatment decision.

Research Review: Neuropsychological functioning in young anorexia nervosa: A meta-analysis

BACKGROUND

Cognitive inflexibility and compulsive behaviours are commonly observed in patients with anorexia nervosa (AN) and are often considered to be caused by impairments in executive functioning and visuospatial processing. Despite an increasing number of young individuals presenting with AN, there is a lack of meta-analytic evidence on the neuropsychological functioning in this population. Our primary aim was to review and synthesize the differences in neuropsychological test performance between young people with AN and healthy controls, and to explore potential moderators.

METHODS

A database search following PRISMA guidelines of MEDLINE, PsycINFO, ISI Web of Science and Epistemonikos was conducted. Hedges' g served as an effect size indicating the standardized mean differences. We utilized mixed-effects meta-regression and machine learning meta-analyses to identify relevant moderators.

RESULTS

Sixteen studies met the inclusion criteria with a total of 1333 participants (665 with AN) and 59 effect sizes. Random-effects meta-analyses demonstrated a small and insignificant difference between young individuals with AN and controls ( g¯  = -0.144, 95% CI [-0.328, 0.041]) in overall neuropsychological functioning. However, the difference was significant for the cognitive domains of memory, working memory and visuospatial abilities. Moderator and machine-learning analyses revealed a stronger negative effect in older participants and moderator effects of country and assessment quality.

CONCLUSIONS

Our findings highlight the significant impact of age on neuropsychological test performance in patients with AN. There is a need for a more widespread inclusion of potentially confounding variables in primary studies as well as instruments specifically targeted at younger populations.