Genetic analysis of bulimia nervosa: methods and sample description

40 years of research on eating disorders in domain-specific journals: Bibliometrics, network analysis, and topic modeling

Previous studies have used a query-based approach to search and gather scientific literature. Instead, the current study focused on domain-specific journals in the field of eating disorders. A total of 8651 documents (since 1981 to 2020), from which 7899 had an abstract, were retrieved from: International Journal of Eating Disorders (n = 4185, 48.38%), Eating and Weight Disorders (n = 1540, 17.80%), European Eating Disorders Review (n = 1461, 16.88%), Eating Disorders (n = 1072, 12.39%), and Journal of Eating Disorders (n = 393, 4.54%). To analyze these data, diverse methodologies were employed: bibliometrics (to identify top cited documents), network analysis (to identify the most representative scholars and collaboration networks), and topic modeling (to retrieve major topics using text mining, natural language processing, and machine learning algorithms). The results showed that the most cited documents were related to instruments used for the screening and evaluation of eating disorders, followed by review articles related to the epidemiology, course and outcome of eating disorders. Network analysis identified well-known scholars in the field, as well as their collaboration networks. Finally, topic modeling identified 10 major topics whereas a time series analysis of these topics identified relevant historical shifts. This study discusses the results in terms of future opportunities in the field of eating disorders.

Body Dissatisfaction and Disordered Eating among College Women in China, South Korea, and the United States: Contrasting Predictions from Sociocultural and Feminist Theories

Body dissatisfaction and disordered eating were compared across groups of college women from China ( n = 109), South Korea ( n = 137), and the United States ( n = 102). Based on cultural differences in the amount of exposure to Western appearance standards, particularly the thin-body ideal, sociocultural theory ( Thompson, Heinberg, Altabe, & Tantleff-Dunn, 1999 ) would predict that body dissatisfaction and disordered eating would be highest in the U.S. sample and lowest in the Chinese sample. In contrast, based on the speed and pervasiveness of changes in women's roles, feminist theory ( Bordo, 1993 ; Jeffreys, 2005 ) would predict that body dissatisfaction and disordered eating would be highest in the Korean sample and lowest in the U.S. sample. Multidimensional measures indicated the highest levels of body dissatisfaction and disordered eating in the Korean sample and the lowest levels in the U.S. sample, indicating that predictions derived from feminist theory were a better fit to the data than predictions derived from sociocultural theory. Results indicated that theoretical understandings of body dissatisfaction must recognize not only differences between Western and non-Western cultures, but also differences among non-Western cultures.

Machine learning derived risk prediction of anorexia nervosa

Background

Anorexia nervosa (AN) is a complex psychiatric disease with a moderate to strong genetic contribution. In addition to conventional genome wide association (GWA) studies, researchers have been using machine learning methods in conjunction with genomic data to predict risk of diseases in which genetics play an important role.

Methods

In this study, we collected whole genome genotyping data on 3940 AN cases and 9266 controls from the Genetic Consortium for Anorexia Nervosa (GCAN), the Wellcome Trust Case Control Consortium 3 (WTCCC3), Price Foundation Collaborative Group and the Children’s Hospital of Philadelphia (CHOP), and applied machine learning methods for predicting AN disease risk. The prediction performance is measured by area under the receiver operating characteristic curve (AUC), indicating how well the model distinguishes cases from unaffected control subjects.

Results

Logistic regression model with the lasso penalty technique generated an AUC of 0.693, while Support Vector Machines and Gradient Boosted Trees reached AUC’s of 0.691 and 0.623, respectively. Using different sample sizes, our results suggest that larger datasets are required to optimize the machine learning models and achieve higher AUC values.

Conclusions

To our knowledge, this is the first attempt to assess AN risk based on genome wide genotype level data. Future integration of genomic, environmental and family-based information is likely to improve the AN risk evaluation process, eventually benefitting AN patients and families in the clinical setting.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-016-0165-x) contains supplementary material, which is available to authorized users.

Determining empirical thresholds for "definitely large" amounts of food for defining binge-eating episodes

Binge episodes involve "definitely large" amounts of food, yet limited data exist regarding the upper limits of food consumption in non-binge eating episodes. Study 1 examined the concurrent validity of a self-report measure developed to measure "usual" food consumption. Results support good concurrent validity for most items across response versions. Study 2 identified the upper limits of normal food consumption (i.e., 85(th) percentile of participants' largest reported usual servings). Thresholds differed across types of foods, and men reported higher thresholds than women for several foods. Type of food and gender should be considered when assessing for "definitely large" amounts of food.

The role of leptin, melanocortin, and neurotrophin system genes on body weight in anorexia nervosa and bulimia nervosa

OBJECTIVE

Although low weight is a key factor contributing to the high mortality in anorexia nervosa (AN), it is unclear how AN patients sustain low weight compared with bulimia nervosa (BN) patients with similar psychopathology. Studies of genes involved in appetite and weight regulation in eating disorders have yielded variable findings, in part due to small sample size and clinical heterogeneity. This study: (1) assessed the role of leptin, melanocortin, and neurotrophin genetic variants in conferring risk for AN and BN; and (2) explored the involvement of these genes in body mass index (BMI) variations within AN and BN.

METHOD

Our sample consisted of 745 individuals with AN without a history of BN, 245 individuals with BN without a history of AN, and 321 controls. We genotyped 20 markers with known or putative function among genes selected from leptin, melanocortin, and neurotrophin systems.

RESULTS

There were no significant differences in allele frequencies among individuals with AN, BN, and controls. AGRP rs13338499 polymorphism was associated with lowest illness-related BMI in those with AN (p = 0.0013), and NTRK2 rs1042571 was associated with highest BMI in those with BN (p = 0.0018).

DISCUSSION

To our knowledge, this is the first study to address the issue of clinical heterogeneity in eating disorder genetic research and to explore the role of known or putatively functional markers in genes regulating appetite and weight in individuals with AN and BN. If replicated, our results may serve as an important first step toward gaining a better understanding of weight regulation in eating disorders.

Factors associated with recovery from anorexia nervosa

Previous studies of prognostic factors of anorexia nervosa (AN) course and recovery have followed clinical populations after treatment discharge. This retrospective study examined the association between prognostic factors--eating disorder features, personality traits, and psychiatric comorbidity--and likelihood of recovery in a large sample of women with AN participating in a multi-site genetic study. The study included 680 women with AN. Recovery was defined as the offset of AN symptoms if the participant experienced at least one year without any eating disorder symptoms of low weight, dieting, binge eating, and inappropriate compensatory behaviors. Participants completed a structured interview about eating disorders features, psychiatric comorbidity, and self-report measures of personality. Survival analysis was applied to model time to recovery from AN. Cox regression models were used to fit associations between predictors and the probability of recovery. In the final model, likelihood of recovery was significantly predicted by the following prognostic factors: vomiting, impulsivity, and trait anxiety. Self-induced vomiting and greater trait anxiety were negative prognostic factors and predicted lower likelihood of recovery. Greater impulsivity was a positive prognostic factor and predicted greater likelihood of recovery. There was a significant interaction between impulsivity and time; the association between impulsivity and likelihood of recovery decreased as duration of AN increased. The anxiolytic function of some AN behaviors may impede recovery for individuals with greater trait anxiety.

Eating Disorders: From Twin Studies to Candidate Genes and Beyond

Substantial effort has been put into the exploration of the biological background of eating disorders, through family, twin and molecular genetic studies. Family studies have shown that anorexia (AN) and bulimia nervosa (BN) are strongly familial, and that familial etiologic factors appear to be shared by both disorders. Twin studies often focus on broader phenotypes or subthreshold eating disorders. These studies consistently yielded moderate to substantial heritabilities. In addition, there has been a proliferation of molecular genetic studies that focused on Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) AN and BN. Seven linkage regions have been identified in genome-wide screens. Many genetic association studies have been performed, but no consistent association between a candidate gene and AN or BN has been reported. Larger genetic association studies and collaborations are needed to examine the involvement of several candidate genes and biological pathways in eating disorders. In addition, twin studies should be designed to assist the molecular work by further exploring genetic determinants of endophenotypes, evaluating the magnitude of contribution to liability of measured genotypes as well as environmental risk factors related to eating disorders. In this manner twin and molecular studies can move the field forward in a mutually informative way.

Neuropsychological psychopathology measures in women with eating disorders, their healthy sisters, and nonrelated healthy controls

OBJECTIVE

To assess the familial influence on neuropsychological dysfunction in eating disorders (ED) patients by comparing 16 patients with restricting type anorexia nervosa (AN-R), 18 patients with bingeing purging type anorexia nervosa, 20 patients with bulimia nervosa binge-purge type, 21 of the patients' nonaffected sisters, and 20 nonrelated healthy controls.

METHODS

Self-report questionnaires assessing psychopathology and 2 computerized cognitive tasks measuring hemispheric asymmetry for language and visuospatial abilities were administered to all participant groups.

RESULTS

On the self-report questionnaires, ED patients scored significantly more pathological than the healthy controls, whereas the healthy sisters were similar to the nonrelated healthy control group. For both of the computerized tasks, the behavior pattern of the sisters was similar to that of all, or most ED groups, and were significantly different from the nonrelated healthy controls. In addition, AN-R patients performed significantly worse on the visuospatial task than the other ED groups.

CONCLUSIONS

The dissociation between the performance on the cognitive tasks and psychopathology measures in healthy sisters, when compared to the ED and nonrelated healthy control groups, suggests that disturbances in neurocognitive functioning in ED patients are not necessarily the result of ED-related dysfunction. Rather, this may indicate general individual differences in cognitive processes that may run in families irrespective of the ED condition of the family member. The findings, with respect to the AN-R patients, support a neurocognitive continuum model of EDs in which AN-R represents the most severe form of the illness.

Genetic association of recovery from eating disorders: the role of GABA receptor SNPs

Follow-up studies of eating disorders (EDs) suggest outcomes ranging from recovery to chronic illness or death, but predictors of outcome have not been consistently identified. We tested 5151 single-nucleotide polymorphisms (SNPs) in approximately 350 candidate genes for association with recovery from ED in 1878 women. Initial analyses focused on a strictly defined discovery cohort of women who were over age 25 years, carried a lifetime diagnosis of an ED, and for whom data were available regarding the presence (n=361 ongoing symptoms in the past year, ie, 'ill') or absence (n=115 no symptoms in the past year, ie, 'recovered') of ED symptoms. An intronic SNP (rs17536211) in GABRG1 showed the strongest statistical evidence of association (p=4.63 × 10(-6), false discovery rate (FDR)=0.021, odds ratio (OR)=0.46). We replicated these findings in a more liberally defined cohort of women age 25 years or younger (n=464 ill, n=107 recovered; p=0.0336, OR=0.68; combined sample p=4.57 × 10(-6), FDR=0.0049, OR=0.55). Enrichment analyses revealed that GABA (γ-aminobutyric acid) SNPs were over-represented among SNPs associated at p<0.05 in both the discovery (Z=3.64, p=0.0003) and combined cohorts (Z=2.07, p=0.0388). In follow-up phenomic association analyses with a third independent cohort (n=154 ED cases, n=677 controls), rs17536211 was associated with trait anxiety (p=0.049), suggesting a possible mechanism through which this variant may influence ED outcome. These findings could provide new insights into the development of more effective interventions for the most treatment-resistant patients.

Association of candidate genes with phenotypic traits relevant to anorexia nervosa

This analysis is a follow-up to an earlier investigation of 182 genes selected as likely candidate genetic variations conferring susceptibility to anorexia nervosa (AN). As those initial case-control results revealed no statistically significant differences in single nucleotide polymorphisms, herein, we investigate alternative phenotypes associated with AN. In 1762 females, using regression analyses, we examined the following: (i) lowest illness-related attained body mass index; (ii) age at menarche; (iii) drive for thinness; (iv) body dissatisfaction; (v) trait anxiety; (vi) concern over mistakes; and (vii) the anticipatory worry and pessimism versus uninhibited optimism subscale of the harm avoidance scale. After controlling for multiple comparisons, no statistically significant results emerged. Although results must be viewed in the context of limitations of statistical power, the approach illustrates a means of potentially identifying genetic variants conferring susceptibility to AN because less complex phenotypes associated with AN are more proximal to the genotype and may be influenced by fewer genes.

Absence of association between specific common variants of the obesity-related FTO gene and psychological and behavioral eating disorder phenotypes

Extensive population-based genome-wide association studies have identified an association between the FTO gene and BMI; however, the mechanism of action is still unknown. To determine whether FTO may influence weight regulation through psychological and behavioral factors, seven single-nucleotide polymorphisms (SNPs) of the FTO gene were genotyped in 1,085 individuals with anorexia nervosa (AN) and 677 healthy weight controls from the international Price Foundation Genetic Studies of Eating Disorders. Each SNP was tested in association with eating disorder phenotypes and measures that have previously been associated with eating behavior pathology: trait anxiety, harm-avoidance, novelty seeking, impulsivity, obsessionality, compulsivity, and concern over mistakes. After appropriate correction for multiple comparisons, no significant associations between individual FTO gene SNPs and eating disorder phenotypes or related eating behavior pathology were identified in cases or controls. Thus, this study found no evidence that FTO gene variants associated with weight regulation in the general population are associated with eating disorder phenotypes in AN participants or matched controls.

Life beyond the eating disorder: education, relationships, and reproduction

OBJECTIVE

We investigated the sociodemographic characteristics in women with and without lifetime eating disorders.

METHOD

Participants were from a multisite international study of eating disorders (N = 2,096). Education level, relationship status, and reproductive status were examined across eating disorder subtypes and compared with a healthy control group.

RESULTS

Overall, women with eating disorders were less educated than controls, and duration of illness and age of onset were associated with educational attainment. Menstrual status was associated with both relationship and reproductive status, but eating disorder subtypes did not differ significantly from each other or from healthy controls on these dimensions.

DISCUSSION

Differences in educational attainment, relationships, and reproduction do exist in individuals with eating disorders and are differentially associated with various eating disorder symptoms and characteristics. These data could assist in educating patients and family members about long-term consequences of eating disorders.

Dietary restraint moderates genetic risk for binge eating

Dietary restraint is a prospective risk factor for the development of binge eating and bulimia nervosa. Although many women engage in dietary restraint, relatively few develop binge eating. Dietary restraint may increase susceptibility for binge eating only in individuals who are at genetic risk. Specifically, dietary restraint may be a behavioral exposure factor that activates genetic predispositions for binge eating. We investigated this possibility in 1,678 young adolescent and adult same-sex female twins from the Minnesota Twin Family Study and the Michigan State University Twin Registry. Twin moderation models were used to examine whether levels of dietary restraint moderate genetic and environmental influences on binge eating. Results indicated that genetic and nonshared environmental factors for binge eating increased at higher levels of dietary restraint. These effects were present after controlling for age, body mass index, and genetic and environmental overlap among dietary restraint and binge eating. Results suggest that dietary restraint may be most important for individuals at genetic risk for binge eating and that the combination of these factors could enhance individual differences in risk for binge eating.

The significance of repetitive hair-pulling behaviors in eating disorders

We studied the relation between intrusive and repetitive hair pulling, the defining feature of trichotillomania, and compulsive and impulsive features in 1,453 individuals with anorexia nervosa and bulimia nervosa. We conducted a series of regression models examining the relative influence of compulsive features associated with obsessive-compulsive disorder, compulsive features associated with eating disorders, trait features related to harm avoidance, perfectionism, and novelty seeking, and self harm. A final model with a reduced sample (n = 928) examined the additional contribution of impulsive attributes. One of 20 individuals endorsed hair pulling. Evidence of a positive association with endorsement of compulsive behavior of the obsessive-compulsive spectrum emerged. Hair pulling may be more consonant with ritualistic compulsions than impulsive urges in those with eating disorders.

Is season of birth related to disordered eating and personality in women with eating disorders?

We assessed the relation between season of birth and eating disorder symptoms and personality characteristics in a sample of 880 women with eating disorders and 580 controls from two Price Foundation Studies. Eating disorder symptoms were assessed using the Structured Interview of Anorexic and Bulimic Disorders and the Structured Clinical Interview for DSM-IV. Personality traits were assessed using the Temperament and Character Inventory and the Frost Multidimensional Perfectionism Scale. Date of birth was obtained from a sociodemographic questionnaire. No significant differences were observed 1) in season of birth across eating disorder subtypes and controls; nor 2) for any clinical or personality variables and season of birth. We found no evidence of season of birth variation in eating disorders symptoms or personality traits. Contributing to previous conflicting findings, the present results do not support a season of birth hypothesis for eating disorders.

Association study of 182 candidate genes in anorexia nervosa

We performed association studies with 5,151 SNPs that were judged as likely candidate genetic variations conferring susceptibility to anorexia nervosa (AN) based on location under reported linkage peaks, previous results in the literature (182 candidate genes), brain expression, biological plausibility, and estrogen responsivity. We employed a case-control design that tested each SNP individually as well as haplotypes derived from these SNPs in 1,085 case individuals with AN diagnoses and 677 control individuals. We also performed separate association analyses using three increasingly restrictive case definitions for AN: all individuals with any subtype of AN (All AN: n = 1,085); individuals with AN with no binge eating behavior (AN with No Binge Eating: n = 687); and individuals with the restricting subtype of AN (Restricting AN: n = 421). After accounting for multiple comparisons, there were no statistically significant associations for any individual SNP or haplotype block with any definition of illness. These results underscore the importance of large samples to yield appropriate power to detect genotypic differences in individuals with AN and also motivate complementary approaches involving Genome-Wide Association (GWA) studies, Copy Number Variation (CNV) analyses, sequencing-based rare variant discovery assays, and pathway-based analysis in order to make up for deficiencies in traditional candidate gene approaches to AN.

Anorexia nervosa trios: behavioral profiles of individuals with anorexia nervosa and their parents

BACKGROUND

Anorexia nervosa (AN) is associated with behavioral traits that predate the onset of AN and persist after recovery. We identified patterns of behavioral traits in AN trios (proband plus two biological parents).

METHOD

A total of 433 complete trios were collected in the Price Foundation Genetic Study of AN using standardized instruments for eating disorder (ED) symptoms, anxiety, perfectionism, and temperament. We used latent profile analysis and ANOVA to identify and validate patterns of behavioral traits.

RESULTS

We distinguished three classes with medium to large effect sizes by mothers' and probands' drive for thinness, body dissatisfaction, perfectionism, neuroticism, trait anxiety, and harm avoidance. Fathers did not differ significantly across classes. Classes were distinguished by degree of symptomatology rather than qualitative differences. Class 1 (approximately 33%) comprised low symptom probands and mothers with scores in the healthy range. Class 2 ( approximately 43%) included probands with marked elevations in drive for thinness, body dissatisfaction, neuroticism, trait anxiety, and harm avoidance and mothers with mild anxious/perfectionistic traits. Class 3 (approximately 24%) included probands and mothers with elevations on ED and anxious/perfectionistic traits. Mother-daughter symptom severity was related in classes 1 and 3 only. Trio profiles did not differ significantly by proband clinical status or subtype.

CONCLUSIONS

A key finding is the importance of mother and daughter traits in the identification of temperament and personality patterns in families affected by AN. Mother-daughter pairs with severe ED and anxious/perfectionistic traits may represent a more homogeneous and familial variant of AN that could be of value in genetic studies.

Schmidt M, Poustka F. Psychiatrische Erkrankungen bei Verwandten von Patienten mit Anorexia nervosa und Bulimia nervosa

Zusammenfassung: Fragestellung: Im deutschen Raum gibt es kaum Familienuntersuchungen von Patienten mit Anorexia und Bulimia nervosa. Methodik: In einer Multizenter Studie wurde das Auftreten psychiatrischer Erkrankungen bei Familienangehörigen 1., 2. und 3. Grades von 65 anorektischen (n = 746) und 21 bulimischen Patienten (n = 265) mit denen von 37 gesunden Kontrollen (n = 480) sowie 11 depressiven Patienten (n = 157) verglichen. Messinstrumente waren u.a. das Diagnostische Interview für Genetische Studien bzw. das Familien Interview für Genetische Studien. Ergebnisse: Die Prävalenz von Anorexia nervosa (signifikant) sowie von depressiven Störungen (Trend) war bei Verwandten 1. und 2. Grades von Patienten mit Essstörungen gegenüber der gesunden Gruppe erhöht. Die meisten Ergebnisse waren eher bei den Familien bulimischer Patienten ausgeprägt. Die Prävalenzraten für psychiatrische Erkrankungen waren insgesamt prozentual niedriger als in vergleichbaren US amerikanischen Stichproben. Schlussfolgerung: Die Ergebnisse könnten für eine familiäre Vulnerabilität bzw. genetisches Risiko von Patienten mit Anorexia und Bulimia nervosa sprechen. Der Zusammenhang des niedrigen Alters der Indexpatienten auf die geringeren Prävalenzraten wird diskutiert.

Influence of overanxious disorder of childhood on the expression of anorexia nervosa

OBJECTIVE

Childhood anxiety often precedes the onset of anorexia nervosa (AN) and may mark a liability to the emergence of an eating disorder for some women. This study investigates the prevalence of overanxious disorder (OAD) among women with AN and explores how OAD impacts AN symptoms and personality traits.

METHOD

Participants were 637 women with AN who completed an eating disorders history, the Structured Clinical Interview for DSM-IV Axis I Disorders, and assessments for childhood anxiety, eating disorder attitudes, and associated personality traits.

RESULTS

Of 249 women (39.1%) reporting a history of OAD, 235 (94.4%) met criteria for OAD before meeting criteria for AN. In comparison to those without OAD, women with AN and OAD self-reported more extreme personality traits and attitudes and they engaged in more compensatory behaviors.

CONCLUSION

Among individuals with AN, those entering AN on a pathway via OAD present with more severe eating disorder pathology.

Impulse control disorders in women with eating disorders

We compared symptom patterns, severity of illness, and comorbidity in individuals with eating disorders with and without impulse control disorders (ICD), and documented the temporal pattern of illness onset. Lifetime ICD were present in 16.6% of 709 women with a history of eating disorders. The most common syndromes were compulsive buying disorder and kleptomania. ICD occurred more in individuals with binge eating subtypes, and were associated with significantly greater use of laxatives, diuretics, appetite suppressants and fasting, and with greater body image disturbance, higher harm avoidance, neuroticism, cognitive impulsivity, and lower self-directedness. In addition, individuals with ICD were more likely to have obsessive-compulsive disorder, any anxiety disorder, specific phobia, depression, cluster B personality disorder, avoidant personality disorder, and to use psychoactive substances. Among those with ICD, 62% reported the ICD predated the eating disorder and 45% reported the onset of both disorders within the same 3-year window. The presence of a lifetime ICD appears to be limited to eating disorders marked by binge eating and to be associated with worse eating-related psychopathology, more pathological personality traits, and more frequent comorbid Axis I and II conditions. Untreated ICD may complicate recovery from eating disorders.

Features associated with diet pill use in individuals with eating disorders

We investigated the relation between diet pill use and eating disorder subtype, purging and other compensatory behaviors, body mass index (BMI), tobacco and caffeine use, alcohol abuse or dependence, personality characteristics, and Axis I and Axis II disorders in 1,345 participants from the multisite Price Foundation Genetics Studies. Diet pill use was significantly less common in women with restricting type of AN than in women with other eating disorder subtypes. In addition, diet pill use was associated with the use of multiple weight control behaviors, higher BMI, higher novelty seeking, and the presence of anxiety disorders, alcohol abuse or dependence, and borderline personality disorder. Findings suggest that certain clinical and personality variables distinguish individuals with eating disorders who use diet pills from those who do not. In the eating disorder population, vigilant screening for diet pill use should be routine clinical practice.

Cannabinoids in eating disorders and obesity

Cannabinoid system is a crucial mechanism in regulating food intake and energy metabolism. It is involved in central and peripheral mechanisms regulating such behavior, interacting with many other signaling systems with a role in metabolic regulation. Cannabinoid agonists promote food intake, and soon a cannabinoid antagonist, rimonabant, will be marketed for the treatment of obesity. It not only causes weight loss, but also alleviates metabolic syndrome. We present a review of current knowledge on this subject, along with data from our own research: genetic studies on this system in eating disorders and obesity and studies locating cannabinoid receptors in areas related to food intake. Such studies suggest cannabinoid hyperactivity in obesity, and this excessive activity may have prognostic implications.

Patterns of menstrual disturbance in eating disorders

OBJECTIVE

To describe menstrual disturbance in eating disorders (ED).

METHOD

We describe menstrual history in 1,705 women and compare eating, weight, and psychopathological traits across menstrual groups.

RESULTS

Menstrual dysfunction occurred across all eating disorder subtypes. Individuals with normal menstrual history and primary amenorrhea reported the highest and lowest lifetime body mass index (BMI), respectively. Normal menstruation and oligomenorrhea groups reported greater binge eating, vomiting, and appetite suppressant use. Amenorrhea was associated with lower caloric intake and higher exercise. Harm avoidance, novelty seeking, perfectionism, and obsessionality discriminated among menstrual status groups. No differences in comorbid Axis I and II disorders were observed.

CONCLUSION

Menstrual dysfunction is not limited to any eating disorder subtype. BMI, caloric intake, and exercise were strongly associated with menstrual function. Menstrual status is not associated with comorbidity. Menstrual irregularity is an associated feature of all ED rather than being restricted to AN only.

D2 dopamine receptor (DRD2) gene Taq1A polymorphism and the eating-related psychological traits in eating disorders (anorexia nervosa and bulimia) and obesity

OBJECTIVE

Food is considered a reinforcing agent, like a variety of substances such as alcohol and other drugs of abuse that produce pleasure. Psychopathological traits related to food intake are demonstrated in eating disorders as in obesity with different genetic aspects for these diseases. Recently, the prevalence of TaqA1 allele has been associated to alcohol, drug abuse and carbohydrate preference. For this reason, the aim of this study was to evaluate if the presence of A1 allele, in eating disorders and obesity, is associated with some particular psycho-pathological characteristics.

METHODS

We studied the presence of TaqA1 in Italian subjects affected by obesity (n=71), anorexia (n=28), bulimia (n=20) and in control group (n=54). The Eating Disorders Inventory (EDI test) was used to evaluate the psychological profiles. Patients without alcohol and drugs abuse were selected (>125 ml/day).

RESULTS

The A1+ allele, both in A1/A1 and A1/A2 genotypes, was not differently distributed among disease groups; on the contrary two EDI subscales (Drive for thinness and Ineffectiveness) resulted associated with A1+ allele without effect of the eating disease or obesity.

CONCLUSION

These results confirm that the presence of A1+ allele is not simply related to body weight but the A1+ allele might be a marker of a genetic psychological condition in people with high risk to develop pathological eating behaviour.

Symptom profile of major depressive disorder in women with eating disorders

OBJECTIVE

Based on the well-documented association between eating disorders (EDs) and affective disorders, the patterns of comorbidity of EDs and major depressive disorder (MDD) were investigated. The temporal relation between EDs and MDD onset was analyzed to determine differences in the course and nature of MDD when experienced prior to versus after the onset of the ED.

METHOD

Lifetime MDD and depressive symptoms were assessed in 1371 women with a history of ED. The prevalence of MDD was first explored across ED subtypes, and ages of onset of MDD and EDs were compared. Depressive symptoms were examined in individuals who developed MDD before and after ED onset.

RESULTS

The lifetime prevalence of MDD was 72.9%. Among those with lifetime MDD (n =963), 34.5% reported MDD onset before the onset of ED. Those who experienced MDD first reported greater psychomotor agitation (OR =1.53; 95%CI =1.14-2.06), and thoughts of own death (but not suicide attempts or ideation; OR =1.73; 95%CI =1.31-2.30). Among individuals who had MDD before ED, 26.5% had the MDD onset during the year before the onset of ED; 67% of individuals had the onset of both disorders within the same 3 year window.

CONCLUSION

Clinicians treating individuals with new-onset ED or MDD should remain vigilant for the emergence of additional psychopathology, especially during the initial 3 year window following the onset of the first disorder.

Smoking in eating disorders

OBJECTIVE

Smoking has been reported as an appetite and weight control method in eating disorders; however, few studies have explored patterns of smoking across subtypes of eating disorders. The aim of this paper was to explore the patterns and prevalence of smoking behavior in 1,524 women from two of the multisite Price Foundation Genetic studies.

METHOD

Smoking behavior was assessed in 306 individuals with anorexia nervosa-restricting type (RAN), 186 with anorexia nervosa-purging type (PAN), 180 with anorexia nervosa and bulimia nervosa (ANBN), 107 with anorexia nervosa-binging type (BAN), 71 individuals with purging type-bulimia nervosa (PBN), and 674 female community controls. We compared smoking prevalence and smoking behaviors across eating disorder (ED) subtypes and in comparison to controls using the Fagerstrom Test of Nicotine Dependence (FTND).

RESULTS

Overall, women with eating disorders reported higher rates of smoking and greater nicotine dependence than controls. Women with binge/purge subtypes of eating disorders reported the highest rates of smoking of all of the subtypes. Smoking in eating disorders was related to impulsive personality traits.

CONCLUSIONS

Women with eating disorders appear to be at increased risk for smoking, particularly those who binge eat and/or purge and display impulsive personality characteristics. Given the high prevalence, the impact of ongoing smoking on maintenance of eating disorders symptoms is worthy of both clinical and research attention.

Eating disorders and women's health: an update

Anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified have a significant impact on the health care and childbearing outcomes of the female population. Primary care contact for gynecologic care, childbearing, or infertility can serve as a critical entry point for the initial recognition of potentially devastating disorders that may result in permanent impairment and/or chronic debilitation. This review addresses the nature and prevalence of eating disorders and the management of pregnancy complicated by an active eating disorder or a history of an eating disorder. Genetic influences and intergenerational transmission of eating disorders are discussed. Finally, the increased risk for postpartum depression among women with a current or past eating disorder is examined. Factors critical to improving pregnancy outcome and reducing the risk for exacerbation or relapse in the postpartum period are identified.

Features associated with excessive exercise in women with eating disorders

OBJECTIVE

Excessive exercise and motor restlessness are observed in a substantial number of patients with eating disorders. This trait has been studied extensively among animal models of activity anorexia nervosa (AN) and may hold particular interest as an endophenotype for AN. We explored features associated with excessive exercise across subtypes of eating disorders.

METHOD

Participants were female probands and affected female relatives from the multi-site international Price Foundation Genetic Studies with diagnoses of AN, bulimia nervosa (BN), and both AN and BN or eating disorder not otherwise specified (ED-NOS) (N=1,857). Excessive exercise was defined based on responses to the Structured Interview for Anorexic and Bulimic Disorders (SIAB).

RESULTS

Among the eating disorder diagnostic groups, excessive exercise was most common among the purging subtype of AN. Individuals who reported excessive exercise also reported lower minimum BMI, younger age at interview, higher scores on anxiety, perfectionism, and eating disorder symptom measures, more obsessions and compulsions, and greater persistence.

CONCLUSION

Excessive exercise may be associated particularly with the purging subtype of AN as well as with a constellation of anxious/obsessional temperament and personality characteristics among women with eating disorders.

Features associated with laxative abuse in individuals with eating disorders

OBJECTIVE

Laxative abuse is common in patients with anorexia and bulimia nervosa and has been associated with longer duration of illness, suicide attempts, impulsivity, and greater eating and general psychopathology. We explored the extent to which laxative abuse was associated with specific psychopathological features across eating disorder subtypes.

METHODS

Participants were 1021 individuals from the multisite, International Price Foundation Genetic Studies. Axis I disorders, personality disorders and traits, and obsessive compulsive features were assessed.

RESULTS

Laxative abuse was associated with worse eating disorder and general psychopathology and higher prevalence of borderline personality disorder (BPD). Symptom level analyses revealed that specific features of BPD, including suicidality and self-harm, feelings of emptiness, and anger, were most strongly associated with laxative abuse.

CONCLUSIONS

The function of laxative abuse may differ across individuals with eating disorders, alternatively serving as a method of purging and a form of self-harm.

Relationships between features associated with vomiting in purging-type eating disorders

OBJECTIVE

Vomiting is a pernicious symptom of eating disorders. We explored the relation between the symptom of vomiting and features of eating disorder course and severity, personality traits, and Axis I and II comorbidity in individuals with purging-type eating disorders.

METHOD

The sample included participants from the multisite, international Price Foundation Genetic Studies, who had an eating disorder diagnosis (anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified) and had data available for the frequency of purging behaviors (n = 1,048). Axis I disorders, personality disorders, trait anxiety, perfectionism, and temperament and character dimensions were included as possible correlates.

RESULTS

The presence of vomiting was associated with less regular laxative use, lower self-directedness, organization, personal standards, and higher novelty seeking.

CONCLUSION

Vomiting remains a prevalent and potentially destructive symptom of eating disorders, with significant dental and medical morbidity. Our findings suggest that certain clinical and personality variables distinguish individuals with purging-type eating disorders who vomit from those who do not, although there were no marked differences in Axis I or II comorbidity. Specifically targeting treatment to decrease duration of exposure to this dangerous symptom continues to be an important clinical objective.

The relation among perfectionism, obsessive-compulsive personality disorder and obsessive-compulsive disorder in individuals with eating disorders

OBJECTIVE

Perfectionism and obsessionality are core features of eating disorders (ED), yet the nature of their relation remains unknown. Understanding the relation between these traits may enhance our ability to identify relevant behavioral endophenotypes for ED.

METHOD

Six-hundred seven individuals with anorexia and bulimia nervosa from the International Price Foundation Genetic Study were assessed for perfectionism, obsessive-compulsive personality disorder (OCPD), and obsessive-compulsive disorder (OCD).

RESULTS

No differences were found across ED subtypes in the prevalence of OCPD and OCD, nor with the association between OCD and OCPD. Perfectionism scores were highest in individuals with OCPD whether alone or in combination with OCD.

CONCLUSION

Perfectionism appears to be more closely associated with obsessive-compulsive personality symptoms rather than OCD. The pairing of perfectionism with OCPD may be a relevant core behavioral feature underlying vulnerability to ED.

Selection of eating-disorder phenotypes for linkage analysis

Vulnerability to anorexia nervosa (AN) and bulimia nervosa (BN) arise from the interplay of genetic and environmental factors. To explore the genetic contribution, we measured over 100 psychiatric, personality, and temperament phenotypes of individuals with eating disorders from 154 multiplex families accessed through an AN proband (AN cohort) and 244 multiplex families accessed through a BN proband (BN cohort). To select a parsimonious subset of these attributes for linkage analysis, we subjected the variables to a multilayer decision process based on expert evaluation and statistical analysis. Criteria for trait choice included relevance to eating disorders pathology, published evidence for heritability, and results from our data. Based on these criteria, we chose six traits to analyze for linkage. Obsessionality, Age-at-Menarche, and a composite Anxiety measure displayed features of heritable quantitative traits, such as normal distribution and familial correlation, and thus appeared ideal for quantitative trait locus (QTL) linkage analysis. By contrast, some families showed highly concordant and extreme values for three variables-lifetime minimum Body Mass Index (lowest BMI attained during the course of illness), concern over mistakes, and food-related obsessions-whereas others did not. These distributions are consistent with a mixture of populations, and thus the variables were matched with covariate linkage analysis. Linkage results appear in a subsequent report. Our report lays out a systematic roadmap for utilizing a rich set of phenotypes for genetic analyses, including the selection of linkage methods paired to those phenotypes.

Linkage analysis of anorexia and bulimia nervosa cohorts using selected behavioral phenotypes as quantitative traits or covariates

To increase the likelihood of finding genetic variation conferring liability to eating disorders, we measured over 100 attributes thought to be related to liability to eating disorders on affected individuals from multiplex families and two cohorts: one recruited through a proband with anorexia nervosa (AN; AN cohort); the other recruited through a proband with bulimia nervosa (BN; BN cohort). By a multilayer decision process based on expert evaluation and statistical analysis, six traits were selected for linkage analysis (1): obsessionality (OBS), age at menarche (MENAR), and anxiety (ANX) for quantitative trait locus (QTL) linkage analysis; and lifetime minimum body mass index (BMI), concern over mistakes (CM), and food-related obsessions (OBF) for covariate-based linkage analysis. The BN cohort produced the largest linkage signals: for QTL linkage analysis, four suggestive signals: (for MENAR, at 10p13; for ANX, at 1q31.1, 4q35.2, and 8q13.1); for covariate-based linkage analyses, both significant and suggestive linkages (for BMI, one significant [4q21.1] and three suggestive [3p23, 10p13, 5p15.3]; for CM, two significant [16p13.3, 14q21.1] and three suggestive [4p15.33, 8q11.23, 10p11.21]; and for OBF, one significant [14q21.1] and five suggestive [4p16.1, 10p13.1, 8q11.23, 16p13.3, 18p11.31]). Results from the AN cohort were far less compelling: for QTL linkage analysis, two suggestive signals (for OBS at 6q21 and for ANX at 9p21.3); for covariate-based linkage analysis, five suggestive signals (for BMI at 4q13.1, for CM at 11p11.2 and 17q25.1, and for OBF at 17q25.1 and 15q26.2). Overlap between the two cohorts was minimal for substantial linkage signals.

Personality in men with eating disorders

OBJECTIVE

This study compares personality variables of men with eating disorders to women with eating disorders.

METHOD

Data were obtained from an international study of the genetics of eating disorders. Forty-two male participants were age-band matched at 1:2 ratio to females from the same study. Personality features were compared between males and females controlling for diagnostic subgroup.

RESULTS

Males with eating disorders appear to be slightly less at risk for perfectionism, harm avoidance, reward dependence, and cooperativeness than females. Few differences were found when diagnostic subgroup was considered.

CONCLUSION

Observed differences in personality variables may help explain the difference in incidence and prevalence of eating disorders in men and women.