Aetiology of anorexia nervosa: from a "psychosomatic family model" to a neuropsychiatric disorder?

Early-onset anorexia nervosa: a scoping review and management guidelines

BACKGROUND

Anorexia nervosa (AN) is a serious multifactorial eating disorder characterized by insufficient nutritional intake to maintain a minimum normal weight for one's age and height, a fear of gaining weight and a distorted body image. It affects mainly adolescents, but a decreased age at diagnosis has been reported, leading to the definition of a rare form of AN called early-onset or prepubertal anorexia nervosa (EOAN; ORPHA 525738), with reported epidemiological and clinical specificity. Current knowledge and specific treatments for this particular condition remain scarce. We aim to summarize the literature review and synthesize actual knowledge on EOAN for preliminary guidelines to harmonize the diagnosis, treatment and follow-up.

METHODS

A scoping literature review was performed from 2010-2021 using PubMed, Web of Science, PsycInfo and Cochrane via the following search terms: (anorexia nervosa) AND (early-onset OR premenarchal OR prepubertal OR childhood). International guidelines were screened for additional hits. Data extraction was limited to findings relevant to the key topic questions: epidemiology and clinical specificities section, diagnosis and initial evaluation section, treatment section, and follow-up and prognosis section.

RESULTS

A total of 1257 titles were retrieved via the initial search strategy. Finally, 42 records were included in the present article (30 articles and 11 international guidelines and 1 literature review). We identified 15 articles relevant for the epidemiology and clinical specificities section, 11 for the diagnosis and initial evaluation section, 3 for the treatment section, and 1 for the follow-up and prognosis section. Despite the growing literature on the epidemiological and clinical features of EOAN, knowledge of specific treatments and prognoses remains scarce in the absence of extensive standardized data collection and few age-specific clinical research protocols. Current international guidelines generally extrapolate strategies proposed for adolescents and young adults to children with a low level of evidence.

CONCLUSIONS

Continuing research efforts in this specific younger population is needed to validate child-specific care strategies, enabling the establishment of age-appropriate recommendations with a higher level of evidence targeting specific determinants and clinical specificities of EOAN.

The loneliness factor in eating disorders: Implications for psychopathology and biological signatures

OBJECTIVES

Eating disorders (ED) are severe psychiatric conditions. While the biological consequences of EDs are well established, including an increase in inflammatory biomarkers, the influence of psychological factors, such as loneliness, has only recently gained attention in research. Loneliness has been associated with more severe psychopathology in ED patients, while its association with inflammatory biomarkers has only been explored in the general population. For these reasons, we aimed to investigate any possible associations between psychological features, trauma, and inflammatory biomarkers with loneliness in people with ED.

METHODS

This study examined the interaction between loneliness, eating psychopathology, and biological markers in people with EDs. A group of 97 female patients with various diagnoses of ED was assessed for loneliness, general and eating psychopathology, traumatic history during childhood, and clinical biomarkers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and urinary-free cortisol (UFC).

RESULTS

The results indicated that individuals with ED who reported moderate to severe loneliness also displayed greater general psychopathology (p = 0.001), weight concerns (p = 0.007), and physical neglect during childhood (p = 0.006). Furthermore, people with higher levels of loneliness also had higher inflammatory indexes (ESR p = 0.001, CRP p = 0.027) and were positively correlated with markers of stress reaction such as UFC (p < 0.05).

CONCLUSION

The findings underscore the importance of considering loneliness in the assessment of individuals with an ED. We observed notable associations between loneliness and increased psychopathology (both general and specific to eating), as well as higher levels of inflammation and childhood physical neglect. Addressing loneliness may contribute to improving overall well-being and potentially support recovery. This consideration encompasses both psychological and physical factors that interplay in the clinical presentation of individuals.

Association of serotonin receptor gene polymorphisms with anorexia nervosa: a systematic review and meta-analysis

PURPOSE

Several studies have investigated the association between anorexia nervosa and polymorphisms of genes regulating serotonin neurotransmission, with a focus on the rs6311 polymorphism of 5-HTR2A. However, inconsistent results of these studies and conflicting conclusions of existing meta-analyses complicate the understanding of a possible association. We have updated these results and evaluated the involvement of other serotonin receptor gene polymorphisms in anorexia nervosa.

METHODS

Adhering to PRISMA guidelines, we have searched studies on anorexia nervosa and serotonin-regulating genes published from 1997 to 2022, selected those concerning receptor genes and meta-analyzed the results from twenty candidate gene studies on the 5-HTR2A rs6311 polymorphism and the 5-HTR2C rs6318 polymorphism.

RESULTS

Present analyses reveal an association for the 5-HTR2A rs6311 polymorphism, with G and A alleles, across eighteen studies (2049 patients, 2877 controls; A vs. G allele, Odds Ratio = 1.24; 95% Confidence Interval = 1.06-1.47; p = 0.009). However, after geographic subgrouping, an association emerged only in a Southern European area, involving five studies (722 patients, 773 controls; A vs. G allele, Odds Ratio = 1.82; 95% Confidence Interval = 1.41-2.37; p < 0.00001). No association was observed for the 5-HTR2C rs6318 polymorphism across three studies.

CONCLUSIONS

To date, the involvement in the pathophysiology of anorexia nervosa of the 5-HTR2A rs6311 polymorphism appears limited to a specific genetic and/or environmental context, while that of the 5-HTR2C rs6318 polymorphism seems excluded. Genome-wide association studies and epigenetic studies will likely offer deeper insights of genetic and environmental factors possibly contributing to the disorder.

LEVEL OF EVIDENCE

III Evidence obtained from well-designed cohort or case-control analytic studies. Clinical trial registration PROSPERO registration number: CRD42021246122.

The role of the brain-derived neurotrophic factor (BDNF) in anorexia nervosa

The brain-derived neurotrophic factor (BDNF) is a growth factor belonging to the neurotrophin family which plays a pivotal role in the differentiation, survival, and plasticity of neurons in the central nervous system. Evidence suggests that BDNF is an important signal molecule in the regulation of energy balance and thus implicated in body weight control. The discovery of BDNF-expressing neurons in the paraventricular hypothalamus which is important in the regulation of energy intake, physical activity, and thermogenesis gives more evidence to the suggested participation of BDNF in eating behavior. Until now it remains questionable whether BDNF can be used as a reliable biomarker for eating disorders such as anorexia nervosa (AN) as available findings on BDNF levels in patients with AN are ambiguous. AN is an eating disorder characterized by a pathological low body weight in combination with a body image disturbance typically developing during adolescence. A severe drive for thinness leads to restrictive eating behavior often accompanied by physical hyperactivity. During therapeutic weight restoration an increase of BDNF expression levels seems desirable as it might improve neuronal plasticity and survival which is essential for learning processes and thereby essential for the success of the psychotherapeutic treatment of patients. On the contrary, the well-known anorexigenic effect of BDNF might favor relapse in patients as soon as the BDNF levels significantly increase during weight rehabilitation. The present review summarizes the association between BDNF and general eating behavior and especially focuses on the eating disorder AN. In this regard findings from preclinical AN studies (activity-based anorexia model) are outlined as well.

Randomized controlled trial of cognitive remediation therapy in adolescent inpatients with anorexia nervosa: Neuropsychological outcomes

OBJECTIVE

Neuropsychological dysfunction exists in anorexia nervosa (AN). Cognitive Remediation Therapy (CRT), mainly evaluated in adults with AN, targets these impairments.

METHODS

Adolescent inpatients (age = 11-17 years) with AN were randomized to 5 weeks of either 10 sessions of individually delivered CRT or non-specific cognitive-training (NSCT). Co-primary outcomes included cognitive domain 'flexibility' [composite score of Wisconsin Card Sorting Test (WSCT) and Trail Making Test (TMT-4)] and 'central coherence' [composite score of Central Coherence Index (CCI) and Group Embedded Figures Test (GEFT)] at end of treatment (FU1). Secondary outcomes included individual test scores and self-reported everyday-life flexibility at FU1 and at 6-months post-treatment (FU2). Independent sample t-tests, Pearson chi-square-tests and mixed models for repeated measures (MMRM) analyses were conducted.

RESULTS

In 56 females (age = 15.1 ± 1.5 years), CRT was not superior to NSCT at FU1 regarding 'flexibility' (p = 0.768) or 'central coherence' (p = 0.354), nor at FU2 (p = 0.507; p = 0.624) (effect sizes = 0.02-0.26). Both groups improved over time in central coherence (CCI p = 0.001; GEFT p < 0.001), self-reported flexibility (p = 0.002) and WCST (p = 0.18), but not TMT-4 (p = 0.286). NSCT was superior to CRT regarding self-reported planning/organisation ability at FU1 (p < 0.001) and FU2 (p = 0.003).

CONCLUSIONS

CRT was not superior to NSCT in adolescent inpatients with AN. More randomized controlled studies are needed.

Anorexia nervosa: Outpatient treatment and medical management

Anorexia nervosa (AN) is a disabling, costly and potentially deadly illness. Treatment failure and relapse are common after completing treatment, and a substantial proportion of patients develop severe and enduring AN. The time from AN debut to the treatment initiation is normally unreasonably long. Over the past 20 years there has been empirical support for the efficacy of several treatments for AN. Moreover, outpatient treatment with family-based therapy or individual psychotherapy is associated with good outcomes for a substantial proportion of patients. Early intervention improves outcomes and should be a priority for all patients. Outpatient treatment is usually the best format for early intervention, and it has been demonstrated that even patients with severe or extreme AN can be treated as outpatients if they are medically stable. Inpatient care is more disruptive, more costly, and usually has a longer waiting list than does outpatient care. The decision as to whether to proceed with outpatient treatment or to transfer the patient for inpatient therapy may be difficult. The core aim of this opinion review is to provide the knowledge base needed for performing safe outpatient treatment of AN. The scientific essentials for outpatient treatment are described, including how to assess and manage the medical risks of AN and how to decide when transition to inpatient care is indicated. The following aspects are discussed: early intervention, outpatient treatment of AN, including outpatient psychotherapy for severe and extreme AN, how to determine when outpatient treatment is safe, and when transfer to inpatient healthcare is indicated. Emerging treatments, ethical issues and outstanding research questions are also addressed.

Cortisol, Depression, and Anxiety Levels Before and After Short-Term Intensive Nutritional Stabilization in Patients With Severe Anorexia Nervosa

INTRODUCTION

Depression and anxiety are well-known comorbid conditions in patients with anorexia nervosa (AN). Hypercortisolemia in patients with AN may be pathogenic and contribute to depression and anxiety symptomatology.

OBJECTIVE

The aim of this study was to investigate short-term changes in cortisol levels and depression and anxiety symptomatology following intensive re-nutrition in patients with severe AN and hospitalized in a specialized unit. Furthermore, we investigated the potential association between cortisol levels and psychometric parameters.

METHODS

A total of 36 patients with AN were enrolled in the study. Nine dropped out before follow-up. Patients underwent paraclinical and psychometric examinations at admission and discharge. Measurements included plasma cortisol, cortisol binding globulin (CBG), 24-h urine cortisol, and self-report questionnaires regarding eating disorder, depression, anxiety, and stress symptoms. Patients were hospitalized in the unit for somatic stabilization and intensive re-nutrition. Mean admission length was 41 days. The study was registered at ClinicalTrials.gov (NCT02502617).

RESULTS

Cortisol levels in blood and urine did not change from admission to discharge in patients with severe AN. Symptoms of depression, anxiety, stress, and eating disorder remained elevated at discharge. There were no associations between changes in cortisol levels and changes in psychometrics.

DISCUSSION

Our results suggest that short-term intensive re-nutrition did not alter hypothalamic-pituitary-adrenal axis activity or mental health in patients with severe AN. Long-term stabilization and longer follow-up after hospital discharge may be needed to detect changes in cortisol levels and whether these changes are associated with depression and anxiety symptomatology. Greater knowledge about cortisol levels and mental health in patients with severe AN may help in the development of new treatment choices for the chronically ill patients. Future studies could investigate whether cortisol-lowering drugs have a therapeutic effect on mental health in AN.

Toward a Biological, Psychological and Familial Approach of Eating Disorders at Onset: Case-Control ANOBAS Study

Eating disorders (ED) are considered as heterogeneous disorders with a complex multifactor etiology that involves biological and environmental interaction. Objective: The aim was to identify specific ED bio-psychological-familial correlates at illness onset. Methods: A case-control (1:1) design was applied, which studied 50 adolescents diagnosed with ED at onset (12-17 years old) and their families, paired by age and parents' socio-educational level with three control samples (40 with an affective disorder, 40 with asthma, and 50 with no pathology) and their respective families. Biological, psychological, and familial correlates were assessed using interviews, standardized questionnaires, and a blood test. Results: After performing conditional logistic regression models for each type of variable, those correlates that showed to be specific for ED were included in a global exploratory model (R 2 = 0.44). The specific correlates identified associated to the onset of an ED were triiodothyronine (T3) as the main specific biological correlate; patients' drive for thinness, perfectionism and anxiety as the main psychological correlates; and fathers' emotional over-involvement and depression, and mothers' anxiety as the main familial correlates. Conclusion: To our knowledge, this is the first study to use three specific control groups assessed through standardized interviews, and to collect a wide variety of data at the illness onset. This study design has allowed to explore which correlates, among those measured, were specific to EDs; finding that perfectionism and family emotional over-involvement, as well as the T3 hormone were relevant to discern ED cases at the illness onset from other adolescents with or without a concurrent pathology.

Adding maintaining factors to developmental models of anorexia nervosa: An empirical examination in adolescents

OBJECTIVE

A biopsychosocial approach has been proposed to explain the pathogenesis of anorexia nervosa (AN), despite only a few of the existing etiological models having received empirical support. The aim of this study was to empirically investigate Herpertz-Dahlmann, Seitz, and Konrad (2011, https://doi.org/10.1007/s00406-011-0246-y)'s developmental model and to consider if interpersonal reactions to the illness might serve as maintaining factors following the model proposed by Treasure and Schmidt (2013, https://doi.org/10.1186/2050-2974-1-13) METHOD: One hundred adolescents and their families were participated in the study: 50 diagnosed with AN, paired by age and parents' socio-economic status with 50 adolescents without a pathology. Biological, psychological and familial variables were assessed using ten questionnaires and a blood analysis test. Additionally, structural equation modeling was conducted to assess two hypothetical models.

RESULTS

The fit of both models was good after the addition of two covariate parameters (e.g., Comparative Fit Index > 0.96 and Tucker-Lewis Index > 0.95). Premorbid traits were linked to body dissatisfaction and to the number of stressful life events; this in turn was linked to AN symptoms. Biological and familial consequences reinforced this pathology.

CONCLUSIONS

Our findings provide support for both models, suggesting that inter relationships between bio-psycho-familial variables can influence the course of AN during adolescence.

How do you define recovery? A qualitative study of patients with eating disorders, their parents, and clinicians

OBJECTIVE

Recovery from an eating disorder (ED) may be defined differently by different stakeholders. We set out to understand the definition of ED recovery from the perspective of patients, their parents, and clinicians.

METHOD

We recruited patients with EDs (n = 24, ages 12-23 years) representing different diagnoses (anorexia nervosa n = 17, bulimia nervosa n = 4, binge-ED n = 2, avoidant/restrictive food intake disorder n = 1), along with their parents (n = 20), dietitians (n = 11), therapists (n = 14), and primary care providers (n = 9) from three sites: Boston Children's Hospital, University of Michigan C. S. Mott Children's Hospital, and Penn State Hershey Children's Hospital. In-depth, semi-structured, qualitative interviews explored participants' definitions of recovery. Interviews were analyzed using inductive data-driven thematic analysis. Statistical analyses followed to examine the distribution within each theme by respondent type.

RESULTS

Qualitative analysis resulted in the emergence of four overarching themes of ED recovery: (a) psychological well-being, (b) eating-related behaviors/attitudes, (c) physical markers, and (d) self-acceptance of body image. Endorsement of themes two and four did not significantly differ between patients, parents, and clinicians. Clinicians were significantly more likely to endorse theme one (χ² = 9.90, df = 2, p = .007, φ_c = 0.356) and theme three (χ² = 6.42, df = 2, p = .04, φ_c = 0.287) than patients and parents.

DISCUSSION

Our study demonstrates overwhelming support for psychological markers as indicators of ED recovery by all three groups. Clinicians should remain open to additional markers of recovery such as body acceptance and eating-related behaviors/emotions that may be of critical importance to patients and their caregivers.

The Role of Family Relationships in Eating Disorders in Adolescents: A Narrative Review

Background: Adolescents' eating disorders have been explored through various conceptual and empirical models. Only recently, scientific literature in this area has more specifically investigated the role of relationships, with particular attention to family functioning. Objective: This paper reviews family relationships aspects of eating disorders in adolescence. Methods: A narrative literature review of relational issues in adolescents' eating disorders was performed. Results: Empirical evidence of family relationships in adolescents' eating disorders confirms the relevance of relational aspects in the development and maintenance of the pathology. In particular, the contribution of the relational-systemic approach is wide, suggesting the need to refer to the family context for a better understanding of adolescents' sufferance. Additionally, the empirical contributions from the conceptual model of Developmental Psychopathology, highlighting the importance of risk and protection factors in family relationships, provides knowledge about the phenomenon of adolescents' eating disorders in terms of complexity. Conclusions: An integrated relational model aimed to explore adolescents' eating disorders is worthy of investigation to accomplish specific program of intervention.

Evidence for a sex-specific contribution of polygenic load for anorexia nervosa to body weight and prefrontal brain structure in nonclinical individuals

Genetic predisposition and brain structural abnormalities have been shown to be involved in the biological underpinnings of anorexia nervosa (AN). Prefrontal brain regions are suggested to contribute through behavioral inhibition mechanisms to body weight. However, it is unknown if and to which extent biological correlates for AN might be present in individuals without clinical AN symptomatology. We therefore investigated the contribution of polygenic load for AN on body weight and prefrontal brain structure in a sample of n = 380 nonclinical individuals. A polygenic score (PGS) reflecting the individual genetic load for the trait of anorexia nervosa was calculated. Structural MRI data were acquired and preprocessed using the cortical parcellation stream of FreeSurfer. We observed a significant PGS × sex interaction effect on body mass index (BMI), which was driven by a negative correlation between PGS and BMI in female participants. Imaging analyses revealed significant interaction effects of sex  × PGS on surface area of the lateral orbitofrontal cortex (OFC), the pars orbitalis (PO), the rostral middle frontal gyrus (RMF) and the pars triangularis (PT) of the left frontal cortex. The interaction effects were driven by positive correlations between PGS and prefrontal surface areas in female participants and negative correlations in male participants. We furthermore found sex-specific associations between BMI and left RMF surface area as well as between BMI and left PO and left RMF thickness. Our findings demonstrate a sex-specific association between polygenic load for AN, BMI, and prefrontal brain structure in nonclinical individuals. Hence, this study identifies structural abnormalities associated with polygenic load for AN and BMI in brain regions deeply involved in behavioral inhibition and impulse regulation as candidate brain regions for future research.

Sexually dimorphic behavioral effects of maternal separation in anorexic rats

Exposure to negative events during the neonatal period is one of the leading factors contributing to the development of psychiatric disorders, including anorexia nervosa. In this study, we investigated the effects of maternal separation (MS) on the development of anorexia in rodents using the mild-stress form of the activity-based anorexia (ABA) model (2 hr of free access to a running wheel and a 1-hr feeding test) in both male and female rats. We assessed anxiety-like and locomotor behavior and hyperactivity with the open field and elevated plus maze tests. Our results showed that ABA rats of both sexes displayed hyperactive behavior associated with reduced anxiety-like behavior when compared to controls. However, a sexually dimorphic effect of MS emerged in anorexic rats: while the females exposed to MS + ABA were hyperactive with diminished anxiety-related behaviors compared to females of the ABA group, MS in males attenuated or did not alter the effects of the ABA protocol. In conclusion, our data reveal that the synergistic effects of MS and ABA on physical activity and anxiety-like behavior act in opposite directions in the two sexes.

Are family relations connected to the quality of the outcome in adolescent anorexia nervosa? An observational study with the Lausanne Trilogue Play

The study aims to explore the connection between the family interactive patterns, investigated with a standardized observational tool based on a recorded play session, the Lausanne Trilogue Play, and the outcome of adolescent patients with anorexia nervosa after a 6 months treatment, based on the Morgan-Russel Outcome Assessment Schedule. Seventy-two parents and adolescent daughters with anorexia nervosa, consecutively referred to an adolescent neuropsychiatric service, participated in the study and underwent an integrated model of treatment, based on constant neuropsychiatric and dietary monitoring, weekly individual psychotherapy for the daughter, and parental counselling and support. A better adolescents' functioning in family relationships, in particular in the triadic ones, at first assessment, was associated with a better outcome. Data on family interactions may help predict the most appropriate intervention for the patient and his family.

To err is (perfectly) human: behavioural and neural correlates of error processing and perfectionism

The attitude towards one’s own imperfection strongly varies between individuals. Here, we investigated variations in error-related activity depending on two sub-traits of perfectionism, Personal Standard Perfectionism (PSP) and Evaluative Concern Perfectionism (ECP) in a large scale functional magnetic resonance imaging study (N = 75) using a digit-flanker task. Participants with higher PSP scores showed both more post-error slowing and more neural activity in the medial-frontal gyrus including anterior cingulate cortex after errors. Interestingly, high-EC perfectionists with low PSP showed no post-error slowing and the highest activity in the middle frontal gyrus, whereas high-EC perfectionists with high PSP showed the lowest activity in this brain area and more post-error slowing. Our findings are in line with the hypothesis that perfectionists with high concerns but low standards avoid performance monitoring to avoid the worry-inducing nature of detecting personal failure and the anticipation of poor evaluation by others. However, the stronger goal-oriented performance motivation of perfectionists with high concerns and high standards may have led to less avoidance of error processing and a more intense involvement with the imperfect behaviour, which is essential for improving future performance.

Triadic Interactions in Families of Adolescents with Anorexia Nervosa and Families of Adolescents with Internalizing Disorders

The latest studies and practice guidelines for the treatment of adolescent patients with anorexia nervosa agree in pointing out the key role played by parents in determining the young patients’ therapeutic possibilities and outcomes. Still family functioning has usually been studied using only self-reported instruments. The aim of the present study is therefore to investigate the triadic interactions within the families of adolescents with anorexia nervosa using a semi-standardized observational tool based on a recorded play session, the Lausanne Trilogue Play (LTP). Parents and adolescent daughters, consecutively referred to adolescent neuropsychiatric services, participated in the study and underwent the observational procedure (LTP). The 20 families of adolescent girls with anorexia nervosa (restricting type) were compared with 20 families of patients with internalizing disorders (anxiety and depression). The results showed different interactive patterns in the families of adolescents with anorexia nervosa: they had greater difficulties in respecting roles during the play, maintaining the joint attention and in sharing positive affect, especially in the three-together phase (third phase). The majority of these families (12) exhibited collusive alliances. The parental subsystem appeared frequently unable to maintain a structuring role, i.e., providing help, support and guidance to the daughters, while the girls in turn often found it hard to show independent ideas and develop personal projects. Parents experienced difficulty in carving out a couple-specific relational space, from which the ill daughter was at least temporarily excluded also when they were asked to continue to interact with each other, letting the daughter be simply present in a third-part position (fourth phase). The study of the triadic interactions in the families of adolescents with anorexia nervosa may help to shift the attention from the exclusive mother–daughter relation to the involvement of the father, and of the parental couple as a whole. The family functioning is in fact well established as a maintaining factor of anorexia nervosa or vice versa as a facilitating factor in the therapeutic process.

A current view on contactin-4, -5, and -6: Implications in neurodevelopmental disorders

Contactins (Cntns) are a six-member subgroup of the immunoglobulin cell adhesion molecule superfamily (IgCAMs) with pronounced brain expression and function. Recent genetic studies of neuropsychiatric disorders have pinpointed contactin-4 (CNTN4), contactin-5 (CNTN5) and contactin-6 (CNTN6) as candidate genes in neurodevelopmental disorders, particularly in autism spectrum disorders (ASDs), but also in intellectual disability, schizophrenia (SCZ), attention-deficit hyperactivity disorder (ADHD), bipolar disorder (BD), alcohol use disorder (AUD) and anorexia nervosa (AN). This suggests that they have important functions during neurodevelopment. This suggestion is supported by data showing that neurite outgrowth, cell survival and neural circuit formation can be affected by disruption of these genes. Here, we review the current genetic data about their involvement in neuropsychiatric disorders and explore studies on how null mutations affect mouse behavior. Finally, we highlight to role of protein-protein interactions in the potential mechanism of action of Cntn4, -5 and -6 and emphasize that complexes with other membrane proteins may play a role in neuronal developmental functions.

Food matters: how the microbiome and gut-brain interaction might impact the development and course of anorexia nervosa

Anorexia nervosa (AN) is one of the most common chronic illnesses in female adolescents and exhibits the highest mortality risk of all psychiatric disorders. Evidence for the effectiveness of psychotherapeutic or psychopharmacological interventions is weak. Mounting data indicate that the gut microbiome interacts with the central nervous system and the immune system by neuroendocrine, neurotransmitter, neurotrophic and neuroinflammatory afferent and efferent pathways. There is growing evidence that the gut microbiota influences weight regulation and psychopathology, such as anxiety and depression. This article reviews how the gut-brain interaction may impact the development and course of AN. A "leaky gut", characterized by antigens traversing the intestinal wall, was demonstrated in an animal model of AN, and could underlie the low-grade inflammation and increased risk of autoimmune diseases found in AN. Moreover, starvation has a substantial impact on the gut microbiome, and diets used for re-nutrition based on animal products may support the growth of bacteria capable of triggering inflammation. As there is currently no empirically derived agreement on therapeutic re-nourishment in AN, this review discusses how consideration of gut-brain interactions may be important for treatment regarding the determination of target weight, rapidity of weight gain, refeeding methods and composition of the diet which might all be of importance to improve long-term outcome of one of the most chronic psychiatric disorders of adolescence.

Cognitive Flexibility in Juvenile Anorexia Nervosain Relation to Comorbid Symptoms of Depression, Obsessive Compulsive Symptoms and Duration of Illness

OBJECTIVE

Whereas the evidence in adolescents is inconsistent, anorexia nervosa (AN) in adults is characterized by weak cognitive flexibility. This study investigates cognitive flexibility in adolescents with AN and its potential associations with symptoms of depression, obsessive compulsive disorder (OCD), and duration of illness.

METHODS

69 patients and 63 age-matched healthy controls (HC) from 9 till 19 years of age were assessed using the Trail-Making Test (TMT) and self-report questionnaires.

RESULTS

In hierarchical regression analyses, set-shifting ability did not differ between AN and HC, whereas AN patients reported significantly higher rates of depression symptoms and OCD symptoms. Age significantly predicted set-shifting in the total sample. Only among AN patients aged 14 years and older did set-shifting decline with increasing age.

DISCUSSION

The presence of AN with depression or OCD symptoms or the duration of illness do not influence cognitive flexibility in children and adolescents. Early interventions may be helpful to prevent a decline in cognitive flexibility in adolescent AN with increasing age.

Effectiveness of enhanced cognitive behavioral therapy (CBT-E) in the treatment of anorexia nervosa: a prospective multidisciplinary study

BACKGROUND

Anorexia nervosa (AN) is a debilitating psychiatric disorder associated with a wide array of negative health complications and psychiatric comorbidity. Existing evidence for AN treatment in adults is weak, and no empirically supported treatment has been reliably established. The primary objective of this study is to gain knowledge about the effectiveness of enhanced cognitive behavioral therapy (CBT-E) for anorexia nervosa delivered in a public hospital setting. Baseline predictors of treatment outcome and dropout are studied. Furthermore, there will be collected blood and stool samples for a general biobank to be able to initiate research on possible pathophysiological mechanisms underlying AN.

METHODS

The study will assess the potency of outpatient CBT-E in a sample of patients suffering from AN (age >16) admitted to the Section for Eating Disorders at the Department for Psychosomatic Medicine, Haukeland University Hospital in Bergen, Norway. The study has a longitudinal design with five main assessment time points: before treatment, at 3 months, at the end of treatment, at 20 weeks, and at 12 months follow-up including biobank samples. A control group without an eating disorder will also be recruited.

DISCUSSION

Treatment research in a public hospital setting is important for gaining knowledge about the transportability of treatments evaluated in research clinics into ordinary clinical practice. Furthermore, biological material from the thoroughly described patient cohort will serve as a basis for further research on the pathophysiological mechanisms in AN.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02745067 . Registered 14 April 2016. .

New Insights in Anorexia Nervosa

Anorexia nervosa (AN) is classically defined as a condition in which an abnormally low body weight is associated with an intense fear of gaining weight and distorted cognitions regarding weight, shape, and drive for thinness. This article reviews recent evidences from physiology, genetics, epigenetics, and brain imaging which allow to consider AN as an abnormality of reward pathways or an attempt to preserve mental homeostasis. Special emphasis is put on ghrelino-resistance and the importance of orexigenic peptides of the lateral hypothalamus, the gut microbiota and a dysimmune disorder of neuropeptide signaling. Physiological processes, secondary to underlying, and premorbid vulnerability factors-the "pondero-nutritional-feeding basements"- are also discussed.

A systematic review of the existing models of disordered eating: Do they inform the development of effective interventions?

Despite significant advances in the development of prevention and treatment interventions for eating disorders and disordered eating over the last decade, there still remains a pressing need to develop more effective interventions. In line with the 2008 Medical Research Council (MRC) evaluation framework from the United Kingdom for the development and evaluation of complex interventions to improve health, the development of sound theory is a necessary precursor to the development of effective interventions. The aim of the current review was to identify the existing models for disordered eating and to identify those models which have helped inform the development of interventions for disordered eating. In addition, we examine the variables that most commonly appear across these models, in terms of future implications for the development of interventions for disordered eating. While an extensive range of theoretical models for the development of disordered eating were identified (N=54), only ten (18.5%) had progressed beyond mere description and to the development of interventions that have been evaluated. It is recommended that future work examines whether interventions in eating disorders increase in efficacy when developed in line with theoretical considerations, that initiation of new models gives way to further development of existing models, and that there be greater utilisation of intervention studies to inform the development of theory.

Anorexia nervosa: aetiology, assessment, and treatment

Anorexia nervosa is an important cause of physical and psychosocial morbidity. Recent years have brought advances in understanding of the underlying psychobiology that contributes to illness onset and maintenance. Genetic factors influence risk, psychosocial and interpersonal factors can trigger onset, and changes in neural networks can sustain the illness. Substantial advances in treatment, particularly for adolescent patients with anorexia nervosa, point to the benefits of specialised family-based interventions. Adults with anorexia nervosa too have a realistic chance of achieving recovery or at least substantial improvement, but no specific approach has shown clear superiority, suggesting a combination of re-nourishment and anorexia nervosa-specific psychotherapy is most effective. To successfully fight this enigmatic illness, we have to enhance understanding of the underlying biological and psychosocial mechanisms, improve strategies for prevention and early intervention, and better target our treatments through improved understanding of specific disease mechanisms.

Neural responses to kindness and malevolence differ in illness and recovery in women with anorexia nervosa

In anorexia nervosa, problems with social relationships contribute to illness, and improvements in social support are associated with recovery. Using the multiround trust game and 3T MRI, we compare neural responses in a social relationship in three groups of women: women with anorexia nervosa, women in long-term weight recovery from anorexia nervosa, and healthy comparison women. Surrogate markers related to social signals in the game were computed each round to assess whether the relationship was improving (benevolence) or deteriorating (malevolence) for each subject. Compared with healthy women, neural responses to benevolence were diminished in the precuneus and right angular gyrus in both currently-ill and weight-recovered subjects with anorexia, but neural responses to malevolence differed in the left fusiform only in currently-ill subjects. Next, using a whole-brain regression, we identified an office assessment, the positive personalizing bias, that was inversely correlated with neural activity in the occipital lobe, the precuneus and posterior cingulate, the bilateral temporoparietal junctions, and dorsal anterior cingulate, during benevolence for all groups of subjects. The positive personalizing bias is a self-report measure that assesses the degree with which a person attributes positive experiences to other people. These data suggest that problems in perceiving kindness may be a consistent trait related to the development of anorexia nervosa, whereas recognizing malevolence may be related to recovery. Future work on social brain function, in both healthy and psychiatric populations, should consider positive personalizing biases as a possible marker of neural differences related to kindness perception.

Severity of eating disorder symptoms related to oxytocin receptor polymorphisms in anorexia nervosa

Oxytocin is a peptide hormone important for social behavior and differences in psychological traits have been associated with variants of the oxytocin receptor gene in healthy people. We examined whether single nucleotide polymorphisms (SNPs) of the oxytocin receptor gene (OXTR) correlated with clinical symptoms in women with anorexia nervosa, bulimia nervosa, and healthy comparison (HC) women. Subjects completed clinical assessments and provided DNA for analysis. Subjects were divided into four groups: HC, subjects currently with anorexia nervosa (AN-C), subjects with a history of anorexia nervosa but in long-term weight recovery (AN-WR), and subjects with bulimia nervosa (BN). Five SNPs of the oxytocin receptor were examined. Minor allele carriers showed greater severity in most of the psychiatric symptoms. Importantly, the combination of having had anorexia and carrying either of the A alleles for two SNPS in the OXTR gene (rs53576, rs2254298) was associated with increased severity specifically for ED symptoms including cognitions and behaviors associated both with eating and appearance. A review of psychosocial data related to the OXTR polymorphisms examined is included in the discussion. OXTR polymorphisms may be a useful intermediate endophenotype to consider in the treatment of patients with anorexia nervosa.

Inflammatory cytokines and anorexia nervosa: A meta-analysis of cross-sectional and longitudinal studies

OBJECTIVE

Although inflammation is increasingly implicated in psychiatric disorders, less is known about its role in anorexia nervosa (AN), an illness with low body mass index (BMI).

METHODS

We performed a systematic PubMed literature search until 12/31/2013 and meta-analyzed cross-sectional and longitudinal studies comparing circulating pro- and anti-inflammatory cytokines between patients with anorexia nervosa (AN) and healthy controls (HCs) (1) before and (2) after weight gain, and (3) within AN patients before and after weight gain. Standardized mean differences (SMDs)± 95% confidence intervals (CIs) for results from ≥ 2 studies were calculated.

RESULTS

Of 999 initial hits, 22 studies with 924 participants (AN=512, HCs=412) were eligible. Compared to HCs, tumor necrosis factor (TNF)-alpha (SMD=0.35, 95%CI=0.09-0.61, p=0.008), interleukin (IL)1-beta (SMD=0.51, 95%CI=0.18-0.84, p=0.003), IL-6 (SMD=0.43, 95%CI=0.11-0.76, p=0.009), and TNF-receptor-II (SMD=0.42, 95%CI:0.07-0.78, p=0.02) were significantly elevated in AN, while C-reactive protein (SMD=-0.53, 95%CI=-.77, -0.28, p<0.0001) and IL-6 receptor (SMD=-0.85, 95%CI=-1.33, -0.36, p=0.0006) were significantly decreased. No differences were found for TNF-receptor I and TGF-β. Across a subset of eight longitudinal studies (AN=152, HCs=129), significant weight gain (baseline BMI=15.4 ± 1.5, endpoint BMI=18.2 ± 1.6, p<0.0001) was not associated with significant changes in TNF-α, IL-6 and IL1-β. However, after weight gain, IL-6 was not different anymore compared to HCs (SMD=0.06, 95%CI=-0.32, 0.45, p=0.75). In meta-regression, shorter illness duration (p=0.0008), but not younger age (p=0.71) significantly moderated greater IL-6 levels.

CONCLUSION

Despite abnormally low BMI, AN seems to be associated with increased inflammatory cytokines. Whether specific elevated cytokines represent trait or state markers of AN, and whether they could be treatment targets requires further study.

Adolescent eating disorders: update on definitions, symptomatology, epidemiology, and comorbidity

The prevalence of eating disorders among adolescents continues to increase. The starvation process itself is often associated with severe alterations of central and peripheral metabolism, affecting overall health during this vulnerable period. This article aims to convey basic knowledge on these frequent and disabling disorders, and to review new developments in classification issues resulting from the transition to DSM-5. A detailed description is given of the symptomatology of each eating disorder that typically manifests during adolescence. New data on epidemiology, and expanding knowledge on associated medical and psychiatric comorbidities and their often long-lasting sequelae in later life, are provided.

[Hematological changes in adolescent anorexia nervosa]

OBJECTIVE

Hematological changes often occur in patients with acute anorexia nervosa (AN). However, the relationship between these disturbances and other clinical parameters remains unclear.

METHOD

Leucocyte, erythrocyte, and thrombocyte counts as well as hematocrit, hemoglobin, and differential blood counts were collected at admission and after weight restoration in 88 female adolescent patients with the diagnosis of AN according to DSM-IV. These were then compared to clinical parameters.

RESULTS

At admission, there were mild changes in the blood count, most of which, however, were reversible after weight gain. Patients with a greater weight loss, a lower age-adjusted BMI, and a history of taking psychotropic drugs were more likely to develop hematological abnormalities.

CONCLUSIONS

Although most of the hematological changes in adolescent patients with AN were mild, patients with high weight loss and/or low age-adjusted BMI as well as those on psychotropic medication should be monitored carefully in order to avoid severe medical complications. An altered immune function in adult patients with chronic AN might contribute to a higher rate of infections and thus to an increased mortality.

Bone disease in anorexia nervosa

Anorexia nervosa is a serious psychiatric disorder accompanied by high morbidity and mortality. It is characterized by emaciation due to self-starvation and displays a unique hormonal profile. Alterations in gonadal axis, growth hormone resistance with low insulin-like growth factor I levels, hypercortisolemia and low triiodothyronine levels are almost universally present and constitute an adaptive response to malnutrition. Bone metabolism is likewise affected resulting in low bone mineral density, reduced bone accrual and increased fracture risk. Skeletal deficits often persist even after recovery from the disease with serious implications for future skeletal health. The pathogenetic mechanisms underlying bone disease are quite complicated and treatment is a particularly challenging task.

Growing up is hard: mental disorders in adolescence

BACKGROUND

Puberty brings on many biological, mental, and social changes. In this phase of life, the prevalence of serious mental disorders is about 10%.

METHODS

This review is based on a selective search for publications on the prevalence, causes, risk factors, and effects of mental disorders in adolescence.

RESULTS

Internalizing mental disorders are more common in girls; these include depression, social anxiety, and eating disorders. Their prevalence ranges from 12% to 23%, depending on the particular diagnostic instruments and criteria that are applied. Disruptive disorders, e.g., disorders of social behavior, are more common in boys, with a worldwide prevalence of approximately 5% to 10%. Marked differences between the sexes appear during puberty. The one-year prevalence of self-injurious behavior is about 14% in boys and 25% in girls. The consumption of legal and illegal drugs is one of the risk-seeking behaviors associated with adolescence.

CONCLUSION

In routine check-ups and medical office visits, particular attention should be paid to the possibility of a mental disorder. Special outpatient clinics for adolescents can help more young people avail themselves of the existing preventive and therapeutic measures. Early diagnosis and treatment may prevent mental disorders in adulthood and foster age-appropriate development.

Do restrictive and bingeing/purging subtypes of anorexia nervosa differ on central coherence and set shifting?

OBJECTIVE

Anorexia nervosa (AN) has been associated with weak central coherence (CC) and weak set shifting (SS). The main aim of this study was to examine possible differences between restrictive AN (AN-R) and bingeing/purging AN (AN-BP) on these features.

METHODS

A total of 31 patients with AN-R, 20 patients with AN-BP and 26 healthy controls (HC) completed five neuropsychological tests (Block Design, Object Assembly, an adapted task-switching paradigm, Wisconsin Card Sorting Test and Trail Making Test).

RESULTS

Using Block Design and Object Assembly, indicative for CC, AN-R patients performed significantly worse than AN-BP patients and HC, without any difference between AN-BP and HC. On SS measures, no group differences were observed.

DISCUSSION

The results suggest that cognitive profiles of AN-R and AN-BP patients differ significantly on CC and not on SS. Our current findings support the idea that the two subtypes of AN have a distinctive underlying nature and might need a different approach in cognitive remediation.

Anorexia nervosa during adolescence and young adulthood: towards a developmental and integrative approach sensitive to time course

Anorexia nervosa is situated at the junction between two time scales, the time scale of adolescence, in which intense physiological and psychological upheavals are occurring over a relatively short period of time, and the time scale of the potentially chronic evolution of the disease over the course of the patient's lifespan. This second time scale links the critical period of adolescence with the pre-morbid period, during which a complex state of vulnerability, often unseen and unheard, combines with different risk factors, which may be isolated, associated, dissociated or concomitant, to produce the emergence of anorexia; it ushers also adolescence into the period of adulthood, flagged with the reorganization that occurs in the course of the healing process (in case of recovery), or pervaded by somatic and mental distress (in cases where the condition becomes chronic). Given the lifespan nature of the disease, it is difficult to differentiate premorbid pathogenic factors from changes resulting from the acute or chronic phases of the illness. It is also difficult to establish straightforward correlations between physiological disturbances and their clinical consequences, or conversely to assume that the restoration of physiological parameters means the disappearance of the underlying mental disorder. Taken together, these observations support an approach to anorexia nervosa that is both developmental and integrative, taking into account both the complexity of the pathways involved and the developmental timescales of these pathways. This type of approach can help to adjust therapeutic strategies and thus enhance prognosis, in particular by integrating the temporal parameter into the dynamics of care plans.

The role of ghrelin, salivary secretions, and dental care in eating disorders

Eating disorders, including anorexia and bulimia nervosa, are potentially life-threatening syndromes characterized by severe disturbances in eating behavior. An effective treatment strategy for these conditions remains to be established, as patients with eating disorders tend to suffer from multiple relapses. Because ghrelin was originally discovered in the stomach mucosa, it has been widely studied over the past decade in an effort to uncover its potential roles; these studies have shed light on the mechanism by which ghrelin regulates food intake. Thus, studying ghrelin in the context of eating disorders could improve our understanding of the pathogenesis of eating disorders, possibly resulting in a promising new pharmacological treatment strategy for these patients. In addition, early detection and treatment of eating disorders are critical for ensuring recovery of young patients. Oral symptoms, including mucosal, dental, and saliva abnormalities, are typically observed in the early stages of eating disorders. Although oral care is not directly related to the treatment of eating disorders, knowledge of the oral manifestations of eating disorder patients may aid in early detection, resulting in earlier treatment; thus, oral care might contribute to overall patient management and prognosis. Moreover, ghrelin has also been found in saliva, which may be responsible for oral hygiene and digestion-related functions. This review discusses the pharmacological potential of ghrelin in regulating food-intake and the role of saliva and oral care in young patients with eating disorders.

"Not all my fault": genetics, stigma, and personal responsibility for women with eating disorders

Medical researchers and clinicians increasingly understand and present eating disorders (anorexia and bulimia nervosa) as biologically-based psychiatric disorders, with genetic risk factors established by high heritability estimates in twin studies. But there has been no research on interpretation of genetic involvement by people with eating disorders, who may hold other views. Their interpretations are particularly important given the frequent presumption that biogenetic framing will reduce stigma, and recent findings that it exacerbates stigma for other mental illnesses. To identify implications of genetic framing in eating disorders, I conducted semi-structured interviews with 50 US women with a history of eating disorders (half recovered, half in treatment; interviewed 2008-9 in the USA). Interviews introduced the topic of genetics, but not stigma per se. Analysis followed the general principles of grounded theory to identify perceived implications of genetic involvement; those relevant to stigma are reported here. Most anticipated that genetic reframing would help reduce stigma from personal responsibility (i.e., blame and guilt for eating disorder as ongoing choice). A third articulated ways it could add stigma, including novel forms of stigma related to genetic-essentialist effacing of social factors. Despite welcoming reductions in blame and guilt, half also worried genetic framing could hamper recovery, by encouraging fatalistic self-fulfilling prophecies and genetic excuses. This study is the first to elicit perceptions of genetic involvement by those with eating disorders, and contributes to an emerging literature on perceptions of psychiatric genetics by people with mental illness.

Metabolic gray matter changes of adolescents with anorexia nervosa in combined MR proton and phosphorus spectroscopy

INTRODUCTION

There are hints for changes in phospholipid membrane metabolism and structure in the brain of adolescents with anorexia nervosa (AN) using either proton ((1)H) or phosphorus ((31)P) magnetic resonance spectroscopic imaging (MRSI). We aimed to specify these pathological metabolite changes by combining both methods with additional focus on the neuronal metabolites glutamate (Glu) and N-acetyl-l-aspartate (NAA).

METHODS

Twenty-one female patients (mean 14.4  ±  1.9 years) and 29 female controls (mean 16  ±  1.6 years) underwent (1)H and (31)P MRSI at 3 T applied to the centrum semiovale including the anterior cingulate cortex. We assessed gray matter (GM) and white matter (WM) metabolite concentration changes of the frontal and parietal brain measuring choline(Cho)- and ethanolamine(Eth)-containing compounds, Glutamate (Glu) and glutamine (Gln) and their sum (Glx), myoinositol, NAA, and high-energy phosphates.

RESULTS

For (1)H MRSI, a clear discrimination between GM and WM concentrations was possible, showing an increase of Glx (p < 0.001), NAA (frontal p < 0.05), pooled creatine (tCr) (p < 0.001), and choline (tCho) (p < 0.05) in the GM of AN patients. The lipid catabolites glycerophosphocholine (p < 0.07) and glycerophosphoethanolamine (p < 0.03) were increased in the parietal region.

CONCLUSIONS

Significant changes in GM metabolite concentrations were observed in AN possibly triggered by elevated excitotoxin Glu. Increased tCho may indicate modifications of membrane phospholipids due to increased catabolism in the parietal region. Since no significant changes in phosphorylated choline compounds were found for the frontal region, the tCho increase in this region may hint to fluidity changes.