Causes of anorexia nervosa

Associations between parental socioeconomic-, family-, and sibling status and risk of eating disorders in offspring in a Danish national female cohort

OBJECTIVE

Studies on parental socioeconomic status (SES) and family risk factors for eating disorders (EDs) have yielded inconsistent results; however, several studies have identified high parental educational attainment as a risk factor. The aim was to evaluate associations of parental SES and family composition with anorexia nervosa (AN), bulimia nervosa (BN), and eating disorders not otherwise specified (EDNOS) in the offspring, adjusting for parental age and parental mental health.

METHODS

The cohort included women born in Denmark between January 1, 1989 and December 31, 2010, derived from Danish national registers. Each person was followed from their sixth birthday until onset of the disorder of interest or to December 31, 2016. Exposure variables were: childhood SES, defined as individually evaluated parental level of income, occupation, and education; sibling status; and family composition. Outcomes were: AN, BN, EDNOS, and major depressive disorder (MDD), included as a psychiatric comparison disorder. Risks were estimated using Cox proportional hazards.

RESULTS

High parental SES was associated with increased risk of especially AN, and less so BN and EDNOS, in offspring. In comparison, low SES was associated with a higher risk of MDD. No differences between maternal or paternal socioeconomic risk factors were found. Family composition and sibling status showed limited influence on ED risk.

DISCUSSION

SES shows opposite associations with AN than MDD, whereas associations with BN and EDNOS are intermediate. The socioeconomic backdrop of AN differs markedly from that reported in other psychiatric disorders. Whether that is due to genetic and/or environmental factors remains unknown.

PUBLIC SIGNIFICANCE STATEMENT

Parental socioeconomic background (SES) may influence eating disorders risk in offspring somewhat differently than other psychiatric disorders. In Denmark, higher parental SES was associated with increased risk of, particularly, anorexia nervosa (AN). Importantly AN does strike across the SES spectrum. We must ensure that individuals of all backgrounds have equal access to care and are equally likely to be detected and treated appropriately for eating disorders.

Disturbed families or families disturbed: a reconsideration

BACKGROUND

The relationship between anorexia nervosa (AN) and family disturbance has been a subject of debate since its first description. What began as a clear view of the pathologically disturbed family causing AN has become ever more complex over the decades.

OBJECTIVE

The aim of this review is to explore the literature to examine the changes and evolution of clinical opinion around family dysfunction and AN over the last 20 years.

METHODS

A narrative review of heterogeneous studies in peer-reviewed publications sourced from the major databases, including PubMed and ScienceDirect, to illuminate the topic of family distress and AN by highlighting the conflicting and complementary ways it has been studied.

RESULTS

This review has highlighted the complexity of the relationship between anorectic sufferers and their families. It has explored the literature about parental burden, emotions and cognitive mechanisms together with parental attitudes about weight and shape. It is clear that there is no consistent psycho-social pathology in families which has been shown to be causative. However, over the last twenty years, research has highlighted the distress and family dysfunction caused by having to look after an anoretic child with poor mentalisation skills, insecure attachment and emotion dysregulation.

CONCLUSION

The area has become clearer over the last 20 years; research suggests a bi-directional relationship between AN and family dysfunction, with difficult dynamics becoming entrenched within the family. This is best addressed, the consensus suggests, by specialist family therapy and carer skills interventions. Longitudinal research is needed to definitively answer the question with rigorous scientific certainty.

EMB RATING

Level V.

LEVEL OF EVIDENCE

Level I: Evidence obtained from: at least one properly designed randomized controlled trials; systematic reviews and meta-analyses; experimental studies. Level II: Evidence obtained from well-designed controlled trials without randomization. Level III: Evidence obtained from well-designed cohort or case-control analytic studies. Level IV: Evidence obtained from with multiple time series analysis such as case studies. Dramatic results in uncontrolled trials might also be regarded as this type of evidence. Level V: Opinions of respected authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

Attachment and mentalization and their association with child and adolescent eating pathology: A systematic review

OBJECTIVE

Insecure attachment and mentalizing difficulties have been associated with eating pathology in adulthood. However, it is unclear whether eating pathology is associated with attachment or mentalization in children. The aim of this study is to systematically review the literature in this emerging field.

METHOD

Electronic databases were used to search for articles.

RESULTS

Twenty-two studies were identified. In the 15 studies investigating attachment, an association with eating pathology was found in all studies. Mentalizing difficulties and eating pathology were found to be correlated in the seven studies which examined their association.

DISCUSSION

In keeping with the adult literature, cross-sectional studies of children and adolescents consistently report associations with eating pathology. There is some evidence from prospective studies that insecure attachment may be a risk factor for the development of eating pathology in adolescence. The literature on mentalization and eating pathology suggests that adolescents with anorexia nervosa may have difficulties in recognizing emotions. Further research using clinical samples and well-validated measures of attachment and mentalization are required to shed further light on this area.

Integrated circuits and molecular components for stress and feeding: implications for eating disorders

Eating disorders are complex brain disorders that afflict millions of individuals worldwide. The etiology of these diseases is not fully understood, but a growing body of literature suggests that stress and anxiety may play a critical role in their development. As our understanding of the genetic and environmental factors that contribute to disease in clinical populations like anorexia nervosa, bulimia nervosa and binge eating disorder continue to grow, neuroscientists are using animal models to understand the neurobiology of stress and feeding. We hypothesize that eating disorder clinical phenotypes may result from stress-induced maladaptive alterations in neural circuits that regulate feeding, and that these circuits can be neurochemically isolated using animal model of eating disorders.

Anorexia nervosa--a noradrenergic dysregulation hypothesis

Anorexia nervosa manifests a wide range of features which cannot fully be explained on the basis of socio-cultural pressures to be thin, nor by starvation, nor dehydration. Evidence is emerging of a significant neurobiological contribution to its aetiology. However there has to date been no explanation for its pathogenesis that integrates the previously identified genetic, neurobiological and socio-cultural contributing factors. In this paper we propose an empirically-based hypothesis that genetically determined noradrenergic dysregulation, interacting with epigenetic factors, leads to high levels of anxiety, impaired neuroplasticity and regional cerebral hypoperfusion. These, in combination, lead to insula dysfunction. The resulting impairment in insula homuncular representation explains the pathognomonic body image distortion. This distortion, combined with high levels of body-focused anxiety, gives rise to intense dieting, noradrenergic precursor depletion, and initial reduction in anxiety. The subsequent rebound exacerbation of anxiety leads to a vicious cycle of maintenance. Novel treatment implications based on this hypothesis are briefly considered.