Where do eating disorders lie on the diagnostic spectrum and what does it mean?

Similarities and differences between eating disorders and obsessive-compulsive disorder in childhood and adolescence: a systematic review

Background

The developmental age, comprising childhood and adolescence, constitutes an extremely important phase of neurodevelopment during which various psychiatric disorders can emerge. Obsessive-Compulsive Disorder (OCD) and Eating Disorders (ED) often manifest during this critical developmental period sharing similarities but also differences in psychopathology, neurobiology, and etiopathogenesis. The aim of this study is to focus on clinical, genetic and neurobiological similarities and differences in OCD and ED.

Methods

This study is based on a PubMed/MEDLINE and Cochrane Central Register for Controlled Trial (CENTRAL). The research adhered to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Results

The aforementioned search yielded an initial collection of 335 articles, published from 1968 to September 2023. Through the application of inclusion and exclusion criteria, a total of 324 articles were excluded, culminating in a final selection of 10 articles.

Conclusions

Our findings showed both differences and similarities between OCD and ED. Obsessive-compulsive (OC) symptoms are more prevalent in ED characterized by a binge/purge profile than in those with a restrictive profile during developmental age. OC symptomatology appears to be a common dimension in both OCD and ED. When presents, OC symptomatology, exhibits transversal characteristic alterations in the anterior cingulate cortex and poorer cognitive flexibility. These correlations could be highlighted by genetic overlaps between disorders. A comprehensive definition, integrating psychopathological and neurobiological aspects could significantly aid treatment selection and thereby influence the prognosis of these patients.

Locating eating pathology within an empirical diagnostic taxonomy: evidence from a community-based sample

Existing structural models of psychopathology need to be expanded to include additional diagnostic constructs beyond mood, anxiety, substance use, and antisocial behavior disorders. The goal of this study was to locate eating disorders within a hierarchical structural model of psychopathology that is anchored by broad Internalizing and Externalizing factors. Participants were female adolescent twins (N = 1,434) from the Minnesota Twin Family Study. The authors compared the fit of 4 models in which eating disorders (a) defined their own diagnostic class, (b) represented a subclass within Internalizing, (c) formed a subclass within Externalizing, and (d) were allowed to cross-load on both Internalizing and Externalizing. In the best fitting model, eating disorders formed a subfactor within Internalizing. These findings underscore the value of developing more comprehensive empirically based models of psychopathology to increase researchers' understanding of diverse mental disorders.

Quantitative evidence for distinct cognitive impairment in anorexia nervosa and bulimia nervosa

It is generally agreed that at least some aspects of abnormal eating behaviour is indeed due in part to disordered cognition. The accumulated literature illustrates cognitive impairment in patients with anorexia nervosa (AN) and bulimia nervosa (BN). Yet beyond being inconsistent, these independent studies also do not reveal the magnitude of impairment within and across studies and fail to give due consideration to the magnitude of impairment so as to understand the severity and breadth of impairment and/or differences in cognitive profiles between patients with AN and BN. Hence, the present review on the subject sought to articulate the magnitude of cognitive impairment in patients with AN and BN by quantitatively synthesizing the existing literature using meta-analytic methodology. The results demonstrate modest evidence of cognitive impairment specific to AN and BN that is related to body mass index in AN in terms of its severity, and is differentially impaired between disorders. Together, these results suggest that disturbed cognition is figural in the presentation of eating disorders and may serve to play an integral role in its cause and maintenance. Implications of these findings with respects to future research are discussed.

Interspecies genetics of eating disorder traits

Family and twin studies have indicated that genetic factors play a role in the development of eating disorders, such as anorexia and bulimia nervosa, but novel views and tools may enhance the identification of neurobiological mechanisms underlying these conditions. Here we propose an integrative genetic approach to reveal novel biological substrates of eating disorder traits analogous in mouse and human. For example, comparable to behavioral hyperactivity that is observed in 40-80% of anorexia nervosa patients, inbred strains of mice with different genetic backgrounds are differentially susceptible to develop behavioral hyperactivity when food restricted. In addition, a list of characteristics that are relevant to eating disorders and approaches to their measurement in humans together with potential analogous rodent models has been generated. Interspecies genetics of neurobehavioral characteristics of eating disorders has the potential to open new roads to identify and functionally test genetic pathways that influence neurocircuits relevant for these heterogeneous psychiatric disorders.

Fathers' parenting, adverse life events, and adolescents' emotional and eating disorder symptoms: the role of emotion regulation

PURPOSE

To investigate the role of emotion regulation in the relation between fathers' parenting (specifically warmth, behavioral control and psychological control) and adolescents' emotional and eating disorder symptoms, after adjustment for controls.

METHODS

A total of 203 11-18 year-old students from a school in a socio-economically disadvantaged area in North-East London completed questionnaires assessing emotional symptoms (measured with the Strengths and Difficulties Questionnaire's (SDQ) Emotional Symptoms Scale), eating disorder symptoms (measured with the Eating Attitudes Test (EAT-26)), difficulties in emotion regulation (measured with the Difficulties in Emotion Regulation Scale (DERS)), and fathers' overprotection and warmth, measured with the Parental Bonding Instrument (PBI), as well as behavioral and psychological control. The confounding variables considered were number of proximal (i.e., during the last year) adverse life events experienced, gender, age, and socio-economic status (eligibility for free school meals).

RESULTS

Adolescents' difficulties in emotion regulation mediated the link between fathers' psychological control and adolescents' emotional symptoms, but not the link between fathers' parenting and adolescents' eating disorder symptoms, which appeared to be more directly linked to fathers' psychological control and number of proximal adverse life events experienced. Proximal adverse life events experienced were also strongly associated with difficulties in emotion regulation.

CONCLUSIONS

The study findings have implications for intervention programs which may prove more fruitful in addressing adolescent emotional problems by targeting underlying emotion regulation abilities, and in addressing adolescent eating disorder symptoms by protecting adolescents with a recent experience of multiple adverse life events. Parenting programs also stand to benefit from the evidence presented in this study that paternal psychological control may have uniquely harmful consequences for adolescent development through the hampering or atrophying of emotion regulation abilities and the encouragement of eating disorders.

Endophenotypes in eating disorders: moving toward etiologically based diagnosis and treatment focused on pathophysiology

It is hoped that the greater understanding neuroscience will bring to the field of psychiatry will lead to a more biologically based system of classification and diagnosis for psychiatric disorders. The clarification of endophenotypes might produce the ‘macros’ from which such a system could be constructed. The aim of this paper is to discuss the evidence for continuities between eating disorders and developmental disorders of childhood (autistic spectrum disorders and attention-deficit hyperactivity disorder) and possible shared endophenotypes. We review the evidence for obsessive–compulsive traits and disinhibition as intermediate phenotypes, and for information-processing styles such as weak set shifting, central coherence, disinhibition and reward sensitivity as possible endophenotypes. Finally we discuss the implications that this has for treatment.