Contributions of the glucocorticoid receptor polymorphism (Bcl1) and childhood abuse to risk of bulimia nervosa

Risk factors for eating disorders: findings from a rapid review

BACKGROUND

Risk factors represent a range of complex variables associated with the onset, development, and course of eating disorders. Understanding these risk factors is vital for the refinement of aetiological models, which may inform the development of targeted, evidence-based prevention, early intervention, and treatment programs. This Rapid Review aimed to identify and summarise research studies conducted within the last 12 years, focusing on risk factors associated with eating disorders.

METHODS

The current review forms part of a series of Rapid Reviews to be published in a special issue in the Journal of Eating Disorders, funded by the Australian Government to inform the development of the National Eating Disorder Research and Translation Strategy 2021-2031. Three databases were searched for studies published between 2009 and 2021, published in English, and comprising high-level evidence studies (meta-analyses, systematic reviews, moderately sized randomised controlled studies, moderately sized controlled-cohort studies, or population studies). Data pertaining to risk factors for eating disorders were synthesised and outlined in the current paper.

RESULTS

A total of 284 studies were included. The findings were divided into nine main categories: (1) genetics, (2) gastrointestinal microbiota and autoimmune reactions, (3) childhood and early adolescent exposures, (4) personality traits and comorbid mental health conditions, (5) gender, (6) socio-economic status, (7) ethnic minority, (8) body image and social influence, and (9) elite sports. A substantial amount of research exists supporting the role of inherited genetic risk in the development of eating disorders, with biological risk factors, such as the role of gut microbiota in dysregulation of appetite, an area of emerging evidence. Abuse, trauma and childhood obesity are strongly linked to eating disorders, however less conclusive evidence exists regarding developmental factors such as role of in-utero exposure to hormones. Comorbidities between eating disorders and mental health disorders, including personality and mood disorders, have been found to increase the severity of eating disorder symptomatology. Higher education attainment, body image-related factors, and use of appearance-focused social media are also associated with increased risk of eating disorder symptoms.

CONCLUSION

Eating disorders are associated with multiple risk factors. An extensive amount of research has been conducted in the field; however, further studies are required to assess the causal nature of the risk factors identified in the current review. This will assist in understanding the sequelae of eating disorder development and in turn allow for enhancement of existing interventions and ultimately improved outcomes for individuals.

Children with Down syndrome: association of Bcl-I polymorphism of nuclear receptor subfamily 3 group C member 1 gene with obesity

BACKROUND

This study aimed to assess the possible association between rs41423247 (Bcl-I) polymorphism in the gene for the human glucocorticoid receptor (GR) called Nuclear Receptor Subfamily 3 Group C Member 1 (NR3C1) with obesity in Egyptian children with and without Down syndrome.

METHODS

The Bcl-I polymorphism was assessed, using real-time PCR, in 300 children divided into four groups: Down-obese, Down-non obese, normal-obese, and normal non-obese.

RESULTS

There was no significant difference between normal-obese and normal-non obese children regarding the Bcl-I genotypes and allele frequencies, while there was a significant difference between Down-obese and Down-non obese children regarding the Bcl-I GC genotype frequency. Again, there was a highly significant difference between Down-obese and normal-non obese children and between children with Down-syndrome (obese and non-obese) and normal children (obese and non-obese) regarding the Bcl-I genotypes and alleles frequencies.

CONCLUSIONS

Our study found a weak association of the G allele of Bcl-I rs41423247 with the presence of obesity among normal Egyptian children, while there was a significant association of the mutant C allele of the Bcl-I rs41423247 with Down syndrome, suggesting a possible association with Down syndrome pathophysiology.

IMPACT

Bcl-I polymorphism is not strikingly associated with obesity in normal children. The GG genotype is higher in obese normal children but without significant difference. The significant increase of the mutant C allele in Down-children than normal children. This may be relevant to Down syndrome's pathophysiology which disturbs the whole genome's balance.

Childhood Maltreatment and Eating Disorders: A Prospective Investigation

OBJECTIVES

To determine whether childhood maltreatment is a risk factor for two eating disorders (anorexia nervosa and bulimia nervosa) using objective and subjective case definitions.

METHODS

Using a prospective cohorts design, children with documented cases of physical abuse, sexual abuse, and neglect (ages 0-11) from 1967 to 1971 in a Midwestern metropolitan county area were matched on age, race, sex, and approximate family socioeconomic status with non-maltreated children. Both groups were followed up. Retrospective self-reports about childhood maltreatment were collected at age 29. DSM-IV anorexia nervosa (AN) and bulimia nervosa (BN) disorders were assessed at age 41 (N = 807). Logistic and linear regression results are reported.

RESULTS

Using documented cases, childhood maltreatment was not a significant risk factor for AN or BN diagnoses or symptoms in adulthood. However, adults who retrospectively reported any maltreatment and physical and sexual abuse reported significantly more symptoms of AN than those who did not.

CONCLUSIONS

The prediction that childhood maltreatment is a risk factor for anorexia nervosa and bulimia nervosa was partially supported in this longitudinal study. While misattribution of cases might have occurred, these results suggest that researchers and clinicians should use caution in drawing inferences about these relationships and designing interventions.

Stressful life events among individuals with a history of eating disorders: a case-control comparison

BACKGROUND

Experiencing stressful life events (SLEs) can negatively impact mental health and increase risk for psychiatric disorders including eating disorders (EDs). Previous research has shown that childhood sexual abuse is associated with some EDs, but less is known about the association between other non-sexual SLEs and EDs.

METHOD

A case-control study of individuals with (n = 495, age mean ± SD = 29.1 ± 9.8 years) and without (n = 395, age = 30.2 ± 11.7) self-reported lifetime history of EDs was conducted to compare history of self-reported SLEs. Participants reported history of sexual (e.g., rape, other sexual assault) and non-sexual (e.g., emotional abuse, assault, bereavement) life events using an adaptation of the Stressful Life Events Screening Questionnaire. Individuals with EDs were divided into ED subtypes along the restricting - binge eating/purging spectrum to examine subtype differences. Logistic regressions were conducted for each SLE and ED subtype to obtain odds ratios (ORs). We report p-values corrected for multiple comparisons.

RESULTS

Exposure to any SLE was significantly more common in individuals with EDs than in controls (OR = 2.47, p < .001). Specifically, rape, other sexual assault, and emotional abuse were significantly more common among individuals with a history of binge-eating/purging ED subtypes (ORs = 2.15-3.58, p's < .01) compared with controls. Furthermore, history of life-threatening disease and loss of a close relative/partner/friend were associated with some ED subtypes. The association between SLEs and EDs was stronger for individuals who had experienced multiple SLEs.

CONCLUSION

By investigating a range of different SLEs, we showed that both sexual and non-sexual SLEs were more common in individuals with a history of EDs (binge-eating/purging subtypes) than controls. Results highlight the importance of assessing a variety of past SLEs in risk assessment for different EDs.

Life-course effects of early life adversity exposure on eating behavior and metabolism

Environmental variations in early life influence brain development, making individuals more vulnerable to psychiatric and metabolic disorders. Early life stress (ELS) has a strong impact on the development of eating behavior. However, eating is a complex behavior, determined by an interaction between signals of energy homeostasis, neuronal circuits involved in its regulation, and circuits related to rewarding properties of the food. Although mechanisms underlying ELS-induced altered feeding behavior are not completely understood, evidence suggest that the effects of ELS on metabolic, mood, and emotional disorders, as well as reward system dysfunctions can contribute directly or indirectly to altered feeding behavior. The focus of this chapter is to discuss the effects of ELS on eating behavior and metabolism, considering different factors that control appetite such as energy homeostasis, hedonic properties of the food, emotional and cognitive status. After highlighting classic studies on the association between ELS and eating behavior alterations, we discuss how exposure to adversity can interact with genetics characteristics to predict variable outcomes.

Loss-of-Control Eating and Obesity Among Children and Adolescents

PURPOSE OF REVIEW

This review summarizes findings on pediatric loss-of-control (LOC) eating and obesity published since 2013 in relation to physiological, socioenvironmental, and psychological factors.

RECENT FINDINGS

LOC eating and obesity are highly comorbid in youth. Genetic and physiological risk factors are associated with the development of LOC eating. Adverse physiological outcomes of LOC eating include increased risk for overweight and obesity and greater dysfunction in components of metabolic syndrome. Socioenvironmental, psychological, and behavioral factors, such as weight-based teasing, dieting, negative affect, emotion dysregulation, and aspects of cognitive functioning, are consistently related to LOC eating in youth, independent of weight. Prospectively, LOC eating may predict the onset of anxiety disorders, depression, and more severe eating psychopathology later in life. Updates on interventions and future directions are discussed. LOC eating may be a key symptom to target adverse physiological and psychological outcomes; however, treatments are limited and require further examination.

BclI polymorphism of the glucocorticoid receptor and adrenal crisis in primary adrenal insufficiency

CONTEXT

Patients with primary adrenal insufficiency (PAI) or congenital adrenal hyperplasia (CAH) are at a high risk of adrenal crisis (AC). Glucocorticoid sensitivity is at least partially genetically determined by polymorphisms of the glucocorticoid receptor (GR).

OBJECTIVES

To determine if a number of intercurrent illnesses and AC are associated with the GR gene polymorphism BclI in patients with PAI and CAH.

DESIGN AND PATIENTS

This prospective, longitudinal study over 37.7 ± 10.1 months included 47 PAI and 25 CAH patients. During the study period, intercurrent illness episodes and AC were documented.

RESULTS

The study period covered 223 patient years in which 21 AC occurred (9.4 AC/100 pat years). There were no significant differences between BclI polymorphisms (CC (n = 29), CG (n = 34) and GG (n = 9)) regarding BMI, hydrocortisone equivalent daily dose and blood pressure. We did not find a difference in the number of intercurrent illnesses/patient year among BclI polymorphisms (CC (1.5 ± 1.4/pat year), CG (1.2 ± 1.2/pat year) and GG (1.6 ± 2.2/pat year)). The occurrence of AC was not significantly different among the homozygous (GG) genotype (32.5 AC/100 pat years), the CC genotype (6.7 AC/100 pat years) and the CG genotype (4.9 AC/100 pat years). Concomitant hypothyroidism was the highest in the GG genotype group (5/9), compared to others (CC (11/29) and CG (11/34)).

CONCLUSIONS

Although sample sizes were relatively small and results should be interpreted with caution, this study suggests that the GR gene polymorphism BclI may not be associated with the frequencies of intercurrent illnesses and AC.

A systematic review and secondary data analysis of the interactions between the serotonin transporter 5-HTTLPR polymorphism and environmental and psychological factors in eating disorders

OBJECTIVES

To summarize and synthesize the growing gene x environment (GxE) research investigating the promoter region of the serotonin transporter gene (5-HTTLPR) in the eating disorders (ED) field, and overcome the common limitation of low sample size, by undertaking a systematic review followed by a secondary data meta-analysis of studies identified by the review.

METHOD

A systematic review of articles using PsycINFO, PubMed, and EMBASE was undertaken to identify studies investigating the interaction between 5-HTTLPR and an environmental or psychological factor, with an ED-related outcome variable. Seven studies were identified by the systematic review, with complete data sets of five community (n = 1750, 64.5% female) and two clinical (n = 426, 100% female) samples combined to perform four secondary-data analyses: 5-HTTLPR x Traumatic Life Events to predict ED status (n = 909), 5-HTTLPR x Sexual and Physical Abuse to predict bulimic symptoms (n = 1097), 5-HTTLPR x Depression to predict bulimic symptoms (n = 1256), and 5-HTTLPR x Impulsiveness to predict disordered eating (n = 1149).

RESULTS

Under a multiplicative model, the low function (s) allele of 5-HTTLPR interacted with traumatic life events and experiencing both sexual and physical abuse (but not only one) to predict increased likelihood of an ED and bulimic symptoms, respectively. However, under an additive model there was also an interaction between sexual and physical abuse considered independently and 5-HTTLPR, and no interaction with traumatic life events. No other GxE interactions were significant.

CONCLUSION

Early promising results should be followed-up with continued cross-institutional collaboration in order to achieve the large sample sizes necessary for genetic research.

Associations between adverse childhood experiences and clinical characteristics of eating disorders

Patients with eating disorders (EDs) frequently report a history of childhood trauma (CT). We investigated whether certain subtypes of CT are associated with more severe features of EDs, independently of psychiatric comorbidity, and whether they act additively. One hundred and ninety-two patients with DSM-V-defined EDs were consecutively recruited. Five clinical characteristics were assessed: restraint, eating, shape and weight concerns on the EDE-Q, and daily functioning. CT was assessed by the childhood traumatism questionnaire. The clinical features were associated with at least one CT subtype (emotional, sexual or physical abuse, emotional neglect). Multivariate analyses adjusted for lifetime comorbid psychiatric disorders revealed that emotional abuse independently predicted higher eating, shape and weight concerns and lower daily functioning, whereas sexual and physical abuse independently predicted higher eating concern. A dose-effect relationship characterised the number of CT subtypes and the severity of the clinical features, suggesting a consistent and partly independent association between CT and more severe clinical and functional characteristics in EDs. Emotional abuse seems to have the most specific impact on ED symptoms. Last, not all CT subtypes have the same impact but they do act additively.

Analyses of the role of the glucocorticoid receptor gene polymorphism (rs41423247) as a potential moderator in the association between childhood overweight, psychopathology, and clinical outcomes in Eating Disorders patients: A 6 years follow up study

Childhood overweight and the SNP rs41423247 of the glucocorticoid receptor gene (GR) were reported to represent predisposing factors for Eating Disorders (EDs). The distribution of the polymorphism was evaluated in 202 EDs patients, and in 116 healthy subjects. The Structured Clinical Interview for the DSM-IV and self-reported questionnaires were administered at the admission to the clinic and at 3 time points (end of a cognitive behavioral therapy, 3 and 6 years follow up). G-allele was associated with childhood overweight, depressive disorder comorbidity, and diagnostic instability. G-allele carriers reporting childhood overweight showed greater frequency of subjective binge eating and emotional eating.

Research Review: What we have learned about the causes of eating disorders - a synthesis of sociocultural, psychological, and biological research

BACKGROUND

Eating disorders are severe psychiatric disorders with a complex etiology involving transactions among sociocultural, psychological, and biological influences. Most research and reviews, however, focus on only one level of analysis. To address this gap, we provide a qualitative review and summary using an integrative biopsychosocial approach.

METHODS

We selected variables for which there were available data using integrative methodologies (e.g., twin studies, gene-environment interactions) and/or data at the biological and behavioral level (e.g., neuroimaging). Factors that met these inclusion criteria were idealization of thinness, negative emotionality, perfectionism, negative urgency, inhibitory control, cognitive inflexibility, serotonin, dopamine, ovarian hormones. Literature searches were conducted using PubMed. Variables were classified as risk factors or correlates of eating disorder diagnoses and disordered eating symptoms using Kraemer et al.'s (1997) criteria.

FINDINGS

Sociocultural idealization of thinness variables (media exposure, pressures for thinness, thin-ideal internalization, thinness expectancies) and personality traits (negative emotionality, perfectionism, negative urgency) attained 'risk status' for eating disorders and/or disordered eating symptoms. Other factors were identified as correlates of eating pathology or were not classified given limited data. Effect sizes for risk factors and correlates were generally small-to-moderate in magnitude.

CONCLUSIONS

Multiple biopsychosocial influences are implicated in eating disorders and/or disordered eating symptoms and several can now be considered established risk factors. Data suggest that psychological and environmental factors interact with and influence the expression of genetic risk to cause eating pathology. Additional studies that examine risk variables across multiple levels of analysis and that consider specific transactional processes amongst variables are needed to further elucidate the intersection of sociocultural, psychological, and biological influences on eating disorders.

Behavioral and neurodevelopmental precursors to binge-type eating disorders: support for the role of negative valence systems

BACKGROUND

Pediatric loss-of-control (LOC) eating is a robust behavioral precursor to binge-type eating disorders. Elucidating precursors to LOC eating and binge-type eating disorders may refine developmental risk models of eating disorders and inform interventions.

METHOD

We review evidence within constructs of the Negative Valence Systems (NVS) domain, as specified by the Research Domain Criteria framework. Based on published studies, we propose an integrated NVS model of binge-type eating-disorder risk.

RESULTS

Data implicate altered corticolimbic functioning, neuroendocrine dysregulation, and self-reported negative affect as possible risk factors. However, neuroimaging and physiological data in children and adolescents are sparse, and most prospective studies are limited to self-report measures.

CONCLUSIONS

We discuss a broad NVS framework for conceptualizing early risk for binge-type eating disorders. Future neural and behavioral research on the developmental trajectory of LOC and binge-type eating disorders is required.

Glucocorticoid receptor polymorphisms and haplotypes and their expression in health and disease

Cortisol is involved in many physiological processes, including immunosuppressive and anti-inflammatory actions, and therefore cortisol and its synthetic analogs are widely used to treat a large number of diseases. In glucocorticoid treatment, a large variability of clinical responses is observed. This variability may, in part, be ascribed to genetic variation in the glucocorticoid receptor (GR) gene. In this review we present a catalogue of the various single nucleotide polymorphisms (SNPs) in the glucocorticoid receptor gene and their consequences for human health and disease. Many different GR SNP association studies have been described. However, most studies come down to only a few SNPs reported with different annotations. In this review we clarified these different annotations to uniform names. Most associations between GR SNPs and phenotype have been found in body composition, metabolism, the cardiovascular system, the immune system and psychiatric illnesses. However, many associations have not been replicated (yet), and future replication studies and meta-analyses are needed. There is a substantial body of evidence for GR SNPs to have effects on clinical phenotype. However, as most SNP frequencies are low and their variation is within the range of the general population, the impact of a single SNP for health and disease in the general population is probably modest. However, in-depth studying of the molecular mechanisms of repeatedly observed clinical associations could lead to new possibilities for drug development. In particular the development of selective glucocorticoid receptor modulators holds promise.

Methylation of the dopamine D2 receptor (DRD2) gene promoter in women with a bulimia-spectrum disorder: associations with borderline personality disorder and exposure to childhood abuse

OBJECTIVE

Previous findings indicate that women with Bulimia Nervosa (BN), when compared to women with no eating disorder (NED), tend to display elevated methylation in the promoter region of the DRD2 gene. The preceding would be compatible with evidence of generally reduced dopamine activity in people with BN. However, altered DNA methylation has also been associated with adverse environmental exposures (such as to childhood abuse) and with psychiatric disturbances (such as Borderline Personality Disorder: BPD). In this study, we examined the extent to which DRD2 methylation was associated with the presence or absence of a bulimic eating disorder, to childhood abuse exposure, or to comorbid BPD.

METHOD

Women with a bulimia-spectrum disorder (BSD) and women with NED were assessed for childhood traumata, eating-disorder symptoms and BPD, and provided blood samples for methylation analyzes.

RESULTS

BSD and NED groups did not differ as to mean percent DRD2 promoter methylation. However, among the women with a BSD, those with BPD showed small, but significant increases in DRD2 methylation levels compared to women with NED (as indicated by Hochberg's post-hoc tests). Similarly, women with a BSD who reported a history of childhood sexual abuse showed a trend-level elevation of DRD2 methylation compared to our NED group.

DISCUSSION

Our findings imply that, in people with a BSD, increased methylation of the DRD2 gene promoter may be more strongly characteristic of comorbid psychopathology than it is a global correlate of the eating disorder per se. We discuss theoretical implications of our findings.

Psychosocial risk factors for eating disorders

OBJECTIVE

One goal in identifying psychosocial risk factors is to discover opportunities for intervention. The purpose of this review is to examine psychosocial risk factors for disordered eating, placing research findings in the larger context of how etiological models for eating disorders can be transformed into models for intervention.

METHOD

A qualitative literature review was conducted focusing on psychological and social factors that increase the risk for developing eating disorders, with an emphasis on well-replicated findings from prospective longitudinal studies.

RESULTS

Epidemiological, cross-cultural, and longitudinal studies underscore the importance of the idealization of thinness and resulting weight concerns as psychosocial risk factors for eating disorders. Personality factors such as negative emotionality and perfectionism contribute to the development of eating disorders but may do so indirectly by increasing susceptibility to internalize the thin ideal or by influencing selection of peer environment. During adolescence, peers represent self-selected environments that influence risk.

DISCUSSION

Peer context may represent a key opportunity for intervention, as peer groups represent the nexus in which individual differences in psychological risk factors shape the social environment and social environment shapes psychological risk factors. Thus, peer-based interventions that challenge internalization of the thin ideal can protect against the development of eating pathology.

BclI polymorphism of the glucocorticoid receptor gene is associated with increased bone resorption in patients on glucocorticoid replacement therapy

CONTEXT

Patients with primary adrenal insufficiency (PAI) and patients with congenital adrenal hyperplasia (CAH) receive weight-adapted standard glucocorticoid replacement therapy. Clinically, some patients appear more sensitive to therapeutic administration of glucocorticoids than others. Glucocorticoid sensitivity is at least partially genetically determined by polymorphisms of the glucocorticoid receptor (GR) and might influence bone mineral density (BMD).

OBJECTIVES

To determine if bone turnover markers and BMD are associated with the GR gene polymorphism BclI in patients with PAI and CAH.

DESIGN AND PATIENTS

A prospective, cross-sectional study including 74 PAI and 38 CAH patients. BMD was evaluated by DXA. Serum levels of bone turnover markers, minerals, vitamins and hormones, and urinary crosslinks were measured.

RESULTS

Patients carrying the homozygous BclI polymorphism (GG) had significantly higher serum β-CrossLaps (0.37 ± 0.34 μg/l; P < 0.05) and urinary collagen crosslinks (NTX, 68.1 ± 32.4 nmol/g; P < 0.005) despite receiving the lowest average daily hydrocortisone dose of 9.9 ± 3.7 mg/m(2) (P < 0.05). The GG genotype occurred significantly more frequently in patients with increased NTX (OR=6.7, 95% CI = 1.78-25.38) than in patients with normal NTX. However, BMD was not significantly different between different allelic variants. No significant differences in associations of the genotypes with outcomes (or in clinical characteristics) were found between the sexes.

CONCLUSIONS

Although the sample sizes were relatively small and the results should be interpreted with caution, this study suggests that the homozygous (GG) genotype may be associated with higher bone resorption in adult PAI and CAH patients. GG-carriers needed a lower hydrocortisone dose on average supporting the concept that this GR variant is associated with increased cortisol sensitivity.

Methylation of the glucocorticoid receptor gene promoter in bulimic women: associations with borderline personality disorder, suicidality, and exposure to childhood abuse

OBJECTIVE

To compare levels of methylation of the glucocorticoid receptor (GR) gene (NR3C1) promoter between women with bulimia nervosa (BN) and women with no eating disorder (ED), and also to explore, in women with BN, the extent to which methylation of the GR gene promoter corresponds to childhood abuse, suicidality, or borderline personality disorder (BPD).

METHOD

We measured methylation levels in selected NR3C1 promoter regions using DNA obtained from lymphocytes in 64 women with BN (32 selected as having a history of severe childhood abuse and 32 selected as having no such history) and 32 comparison women with no ED or history of childhood abuse.

RESULTS

Compared to noneating disordered women, women with BN and comorbid BPD (or BN with a history of suicidality) showed significantly more methylation of specific exon 1C sites. There was also a (nonsignificant) result indicative of greater methylation in some 1C sites among women with BN, when compared (as a group) to women with no ED. No parallel effects owing to childhood abuse were observed.

DISCUSSION

Our findings associate BN (when accompanied by BPD or suicidality) with hypermethylation of certain GR exon 1C promoter sites. We discuss theoretical and clinical implications of our findings.

Dopamine-system genes, childhood abuse, and clinical manifestations in women with Bulimia-Spectrum Disorders

OBJECTIVE

We explored interaction effects involving polymorphisms of targeted dopamine system genes and selected forms of childhood abuse (sexual, physical and emotional) acting upon severity of binge-eating and psychopathological symptoms in women with Bulimia-Spectrum Disorders (BSDs).

METHODS

Women diagnosed with a BSD (n = 216) were assessed for childhood traumata, eating-disorder (ED) symptoms, and selected psychopathological features (sensation seeking, impulsivity, compulsivity and affective instability), and then provided blood samples for genotyping of main polymorphisms of dopamine-2 receptor (DRD2), dopamine transporter (DAT1) and catechol o-methyltransferase (COMT) genes.

RESULTS

Sensation Seeking was elevated in carriers of the low-function allele of the DRD2 Taq1A polymorphism who also reported childhood sexual abuse, relative to that in individuals showing other combinations of alleles and abuse exposures. In addition, carriers of a low-function allele of COMT scored higher on compulsivity, lower on impulsivity, and marginally lower on frequency of binge-eating than did individuals in whom the allele was absent.

DISCUSSION

Our results suggest that genes acting within the dopamine system may contribute, either directly or indirectly (i.e., in interaction with traumatic childhood experiences), to variations in the presentation of comorbid traits and, possibly, of bulimic symptoms.

Cortisol responses on the dexamethasone suppression test among women with Bulimia-spectrum eating disorders: associations with clinical symptoms

INTRODUCTION

Evidence associates Bulimia Nervosa (BN) with altered functioning of the hypothalamic-pituitary-adrenal (HPA) axis, but the clinical implications of such alterations need to be better understood. We contrasted cortisol responses to the dexamethasone suppression test (DST) in bulimic and non-eating disordered women and examined relationships among DST cortisol responses, eating symptoms and co-morbid disturbances.

METHOD

Sixty women with Bulimia Spectrum (BS) Disorders (either BN or normal weight Eating Disorder NOS with regular binge eating or purging) and 54 non-eating disordered women of similar age and body mass index participated in a 0.5 mg DST, and completed interviews and questionnaires assessing eating symptoms and co-morbid psychopathology.

RESULTS

Compared with the normal-eater group, the BS women demonstrated significantly less DST suppression. Among BS women, DST non-suppression was associated with more severe depression, anxiety and eating preoccupations.

CONCLUSIONS

Our findings show BS women to show less DST suppression compared to normal eater women, and results link extent of non-suppression, in BS individuals, to severity of depression, anxiety and eating preoccupations.

Sex, stress, and mood disorders: at the intersection of adrenal and gonadal hormones

The risk for neuropsychiatric illnesses has a strong sex bias, and for major depressive disorder (MDD), females show a more than 2-fold greater risk compared to males. Such mood disorders are commonly associated with a dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis. Thus, sex differences in the incidence of MDD may be related with the levels of gonadal steroid hormone in adulthood or during early development as well as with the sex differences in HPA axis function. In rodents, organizational and activational effects of gonadal steroid hormones have been described for the regulation of HPA axis function and, if consistent with humans, this may underlie the increased risk of mood disorders in women. Other developmental factors, such as prenatal stress and prenatal overexposure to glucocorticoids can also impact behaviors and neuroendocrine responses to stress in adulthood and these effects are also reported to occur with sex differences. Similarly, in humans, the clinical benefits of antidepressants are associated with the normalization of the dysregulated HPA axis, and genetic polymorphisms have been found in some genes involved in controlling the stress response. This review examines some potential factors contributing to the sex difference in the risk of affective disorders with a focus on adrenal and gonadal hormones as potential modulators. Genetic and environmental factors that contribute to individual risk for affective disorders are also described. Ultimately, future treatment strategies for depression should consider all of these biological elements in their design.

Childhood emotional abuse and eating symptoms in bulimic disorders: an examination of possible mediating variables

OBJECTIVE

We sought to estimate prevalences of childhood emotional abuse (CEA) in bulimic and normal-eater control groups, and to replicate previous findings linking CEA to severity of eating symptoms in BN. We also examined potential mediators of the link between CEA and disordered eating.

METHOD

Women diagnosed with a bulimic disorder (n = 176) and normal-eater women (n = 139) were assessed for childhood traumata, eating-disorder (ED) symptoms and psychopathological characteristics (ineffectiveness, perfectionism, depression, and affective instability) thought to be potential mediators of interest.

RESULTS

CEA was more prevalent in the bulimic than in the nonbulimic group, and predicted severity of some eating-symptom indices. Ineffectiveness and affective instability both mediated relationships between CEA and selected ED symptoms.

DISCUSSION

We found CEA to predict eating pathology through mediating effects of ineffectiveness and affective instability. CEA might influence severity of ED symptoms by impacting an individual's self-esteem and capacity for affect regulation.

Interaction of the BcII glucocorticoid receptor polymorphism and childhood abuse in Bulimia Nervosa (BN): relationship to BN and to associated trait manifestations

We recently documented a gene-environment interaction suggesting that individuals with Bulimia Nervosa (BN) differed from normal eaters as to the combined presence of the low-function allele of the glucocorticoid receptor polymorphism, BcII, and childhood abuse. The present study examined the extent to which any such interaction effect may have been attributable to behavioral impulsivity, sensation seeking, affective instability or depression. We had 174 bulimic and 130 nonbulimic women provide blood for genetic assays, and measured psychopathological traits and childhood abuse using structured interviews and self-report questionnaires. As expected, we observed a significant BcII × abuse interaction indicating genetic and environmental susceptibilities to co-occur significantly more often in bulimic than in nonbulimic individuals. The BcII × abuse interaction was attenuated when levels of depression were accounted for, but was surprisingly unaffected by controls for motoric impulsivity, sensation seeking or affective instability. Our findings suggest that stress-induced alterations in glucocorticoid sensitivity contribute to BN and depressive disturbances--without being associated with the behavioral/affective dysregulation seen in many BN sufferers. We discuss theoretical and clinical implications of these observations.