An investigation of temperament endophenotype candidates for early emergence of the core cognitive component of eating disorders

Can more people be "Happy Being Me"? Testing the delivery of a universal body satisfaction program by clinicians and school staff

The research presented here evaluates the delivery of Happy Being Me (HBM; Dunstan, Paxton & McLean, 2017) with boys and girls in their first year of secondary school in the UK (Year 7 and after comparisons aged 11-12). HBM is a manualised universal prevention programme which aims to improve body dissatisfaction and associated risk factors. Risk factors studied here were internalization of the thin ideal, physical appearance comparisons, appearance conversations. Secondary outcomes measured were self-esteem and eating disorder symptomsStudy 1 tested the effectiveness of HBM (n = 172) compared to a control group (n = 197) who received curriculum as usual. HBM resulted in significantly improved body satisfaction post-intervention which was maintained at follow up. There were no significant changes in risk factors.Study 2 compared clinician (n = 172) and teacher (n = 174) delivery. Students who received clinician-led, but not teacher-led, HBM had improved body satisfaction and this was maintained at follow up. Internalization of the thin ideal and self-esteem, improved in both clinician and teacher-led groups with small to medium sized effects. HBM can be delivered by clinicians independent of programme developers in a heterogeneous sample with positive effects on body satisfaction. Issues arising for wider delivery are discussed.

Current directions in biomarkers and endophenotypes for anorexia nervosa: A scoping review

There are currently no validated biomarkers for anorexia nervosa (AN), though recent literature suggests an increased research interest in this area. Biomarkers are objective, measurable indicators of illness that can be used to assist with diagnosis, risk assessment, and tracking of illness state. Related to biomarkers are endophenotypes, which are quantifiable phenomena that are distinct from symptoms and which link genes to manifest illness. In this scoping review, we sought to provide a summary of recent research conducted in the pursuit of biomarkers and endophenotypes for AN. The findings indicate that a number of possible biomarkers which can assess the presence or severity of AN independently of weight status, including psychophysical (e.g., eye-tracking) and biological (e.g., immune, endocrine, metabolomic, neurobiological) markers, are currently under investigation. However, this research is still in early phases and lacking in replication studies. Endophenotype research has largely been confined to the study of several neurocognitive features, with mixed evidence to support their classification as possible endophenotypes for the disorder. The study of biomarkers and endophenotypes in AN involves significant challenges due to confounding factors of illness-related sequalae, such as starvation. Future research in these areas must prioritise direct evaluation of the sensitivity, specificity and test-retest reliability of proposed biomarkers and enhanced control of confounding physical consequences of AN in the study of biomarkers and endophenotypes.

Common genetic architecture and environmental risk factors underpin the anxiety-disordered eating relationship: Findings from an adolescent twin cohort

OBJECTIVE

Despite established comorbidity between anxiety and disordered eating (DE), and a plethora of research using various methodologies to examine this overlap, use of twin modeling to expose whether a shared genetic liability underpins these conditions remains rare.

METHOD

Data from a longitudinal sample of female twins were selected: measures of risk for DE from Wave 1 (N = 699, 351 pairs, aged 12-15 years), and the Eating Disorder Examination (EDE) and Children's Anxiety Sensitivity Index (CASI) from Wave 2 (N = 669, 338 pairs, aged 16-19 years). At this time, they also completed Children's Anxiety Sensitivity Index (CASI). Bivariate Cholesky decomposition models adjusting for age and body mass index centile investigated the covariance structure between the CASI and EDE.

RESULTS

Modeling both genetic and nonshared environmental influences parsimoniously fit these data. All paths were significant. Additive genetic influences were notable for CASI and EDE phenotypes; 14% of the heritable variance was contributed by CASI to the expression of EDE. There was also a smaller but significant contribution of nonshared environmental influences. A multinomial logistic regression indicated body dissatisfaction (RRR = 1.53; 95% CI = 1.07-2.18) differentiated groups with highest EDE scores from the highest CASI scores.

DISCUSSION

Shared genetic and environmental influences appear to underpin the relationship, and potentially the observed comorbidity, between anxiety sensitivity and DE. The age of onset is typically earlier for anxiety than DE, suggesting a significant opportunity for early intervention work to reduce the likelihood of subsequent development of DE.

Etiological influences on continuity and co-occurrence of eating disorders symptoms across adolescence and emerging adulthood

OBJECTIVE

The role of common and symptom-specific genetic and environmental influences in maintaining eating disorder symptoms across development remains unclear. This study investigates the continuity and change of etiological influences on drive for thinness, bulimia, and body dissatisfaction symptoms and their co-occurrence, across adolescence and emerging adulthood.

METHOD

In total, 2,629 adolescent twins (mean age = 15.20, SD = 1.95) reported eating disorders symptoms across three waves of data collection. Biometric common pathways model was fitted to estimate genetic and environmental contributions to the continuity of each symptom over time, as well as time- and symptom-specific influences.

RESULTS

Drive for thinness and body dissatisfaction symptoms showed a pattern of high continuity across development and high correlations with each other, whereas bulimia symptoms were moderately stable and less associated with the other two symptoms. Latent factors reflecting continuity of each symptom were largely under genetic influence (A_l  = 0.60-0.82). New genetic influences contributing to change in the developmental course of symptoms were observed in emerging adulthood. Genetic influences correlated considerably between the three symptoms. Non-shared environmental influences were largely time-and symptom-specific, but some contributed moderately to the continuity across development (E_l  = 0.18-0.40). The etiological overlap was larger between drive for thinness and body dissatisfaction symptoms than with bulimia symptoms.

DISCUSSION

The results provide preliminary evidence that stable as well as newly emerging genetic influences contribute to the co-occurrence of drive for thinness, bulimia, and body dissatisfaction symptoms across adolescence and emerging adulthood. Conversely, environmental influences were less stable and contributed to change in symptoms over time.

Endophenotypes: A conceptual link between anorexia nervosa and autism spectrum disorder

The paper, by translating the concept and the two models of endophenotype (EP), strengthens the hypothesis that there exists a linkage between anorexia nervosa (AN) and autism spectrum disorder (ASD). Specifically, the paper synthesizes empirical research that supported the idea that individuals with AN and individuals with ASD share similarities with respect to their neurocognitive EPs and temperament EPs. The paper then introduces an innovative structure to emphasize the subtle difference between neurocognitive EPs and temperament EPs in relation to AN and ASD. This structure constitutes the categorization of the shared neurocognitive EPs to the liability-index model of EP and the shared temperament EPs to the mediational model of EP. The paper argues that the shared neurocognitive EPs under the liability index model of EP are trait markers signaling the effects of genes on the phenotypes of AN and ASD; whereas, the shared temperament EPs under the mediational model of EP are state markers describing the symptomatic status of AN and ASD. The proposition of the paper suggests clinicians and researchers should target the atypical state markers (i.e., temperament EPs) shared between AN and ASD when tailoring environment-based treatments for individuals with AN who exhibit autistic behaviors and individuals with ASD who display disordered eating behaviors or anorexic symptoms.

Weight-related peer-teasing moderates genetic and environmental risk and disordered eating: twin study

BackgroundWeight-related peer-teasing is considered a potent prospective risk factor for development of disordered eating and clinical eating disorders. Currently, the interplay between genetic and environmental influences has yet to be elucidated.AimsTo determine whether peer-teasing moderates latent genetic and/or environmental risk for disordered eating among female adolescent twins.MethodFull quantitative gene-environment interplay modelling of longitudinal trajectory of disordered eating in 685 female twins from the Australian Twin Registry.ResultsA model permitting moderation of disordered eating by peer-teasing involving genetic and non-shared environment effects fit these data best. As levels of peer-teasing increased, both genetic and environmental influences on disordered eating strengthened; however, genetic sources increased proportionally more than environmental sources.ConclusionsWeight-related peer-teasing represents a particularly powerful trigger for disordered eating. Nevertheless, it is amenable to intervention/prevention activities spanning individual to universal levels of endeavour.

Changes in genetic and environmental influences on disordered eating between early and late adolescence: a longitudinal twin study

BACKGROUND

We investigated the genetic and environmental contributions to disordered eating (DE) between early and late adolescence in order to determine whether different sources of heritability and environmental risk contributed to these peak times of emergence of eating disorders.

METHOD

Adolescent female twins from the Australian Twin Registry were interviewed over the telephone with the Eating Disorder Examination (EDE). Data were collected at 12-15 and 16-19 years (wave 1: N = 699, 351 pairs; wave 3: N = 499, 247 pairs). Assessments also involved self-report measures related to negative life events and weight-related peer teasing.

RESULTS

Unstandardized estimates from the bivariate Cholesky decomposition model showed both genetic influences and non-shared environmental influences increased over adolescence, but shared environmental influences decreased. While non-shared environmental sources active at ages 12-15 years continued to contribute at 16-19 years, new sources of both additive genetic and non-shared environmental risk were introduced at ages 16-19 years. Weight-related peer teasing in early-mid adolescence predicted increases of DE in later adolescence, while negative life events did not.

CONCLUSIONS

Two-thirds of the heritable influence contributing to DE in late adolescence was unique to this age group. During late adolescence independent sources of genetic risk, as well as environmental influences are likely to be related in part to peer teasing, appear key antecedents in growth of DE.

In double trouble for eating pathology? An experimental study on the combined role of perfectionism and body dissatisfaction

BACKGROUND AND OBJECTIVES

A number of correlational studies suggest that the combined presence of perfectionism and body dissatisfaction creates elevated risk for the development of eating disorder pathology. The aim of this study was to examine the causal role of this combination of risk factors for eating pathology.

METHOD

We conducted an experimental study in a sample of female college students (N = 47). Specifically, we performed an experimental manipulation of perfectionism and examined whether this manipulation would interact with body dissatisfaction to predict eating disorder symptoms.

RESULTS

We found that the effect of the experimental manipulation was moderated by body dissatisfaction, such that women in the perfectionism condition and scoring high on body dissatisfaction exhibited the highest levels of eating disorder symptoms.

LIMITATIONS

The sample was rather small (resulting in limited statistical power) and the participants were predominantly healthy and well-adjusted women, which may limit the generalizability and interpretation of our findings.

CONCLUSIONS

The results suggest that the combination of perfectionism and body dissatisfaction is particularly detrimental and predictive of risk for eating disorder symptoms.

DSM-5 unspecified feeding and eating disorders in adolescents: what do they look like and are they clinically significant?

OBJECTIVE

The recent DSM-5 categorization of eating disorders introduces a new category of eating disorders, Unspecified Feeding and Eating Disorders (UFED), where symptoms do not meet criteria for any other diagnostic category, but cause clinically significant distress or impairment. The aim of the current study was to explore what disorders in UFED might look like in an adolescent population.

METHOD

We examined a large cohort of adolescent female twins (N = 699) who were assessed on three occasions and who did not meet a DSM-5 eating disorder diagnosis but who reported threshold levels of either fasting and/or driven exercise (N = 33; 4.7%). This group of girls was compared to girls who reported no eating disorder over the three waves, and girls who met a diagnosis of either anorexia nervosa (AN) or atypical AN.

RESULTS

The UFED group was characterized as being in the overweight range while striving to lose weight, and placing a high degree of importance on weight and shape in their self-evaluation. This group was indistinguishable from the two eating disorder groups on measures of global eating disorder severity, and demonstrated significantly elevated impairment and distress compared to the no eating disorder group commensurate with the eating disorder groups.

DISCUSSION

Further research of this group is necessary to ensure that these individuals are not overlooked, and that treatment options are appropriate and available.

Body weight status, eating behavior, sensitivity to reward/punishment, and gender: relationships and interdependencies

Behavioral and personality characteristics are factors that may jointly regulate body weight. This study explored the relationship between body mass index (BMI) and self-reported behavioral and personality measures. These measures included eating behavior (based on the Three-Factor Eating Questionnaire; Stunkard and Messick, 1985), sensitivity to reward and punishment (based on the Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) scales) (Carver and White, 1994) and self-reported impulsivity (based on the Barratt Impulsiveness Scale-11; Patton et al., 1995). We found an inverted U-shaped relationship between restrained eating and BMI. This relationship was moderated by the level of disinhibited eating. Independent of eating behavior, BIS and BAS responsiveness were associated with BMI in a gender-specific manner with negative relationships for men and positive relationships for women. Together, eating behavior and BIS/BAS responsiveness accounted for a substantial proportion of BMI variance (men: ∼25%, women: ∼32%). A direct relationship between self-reported impulsivity and BMI was not observed. In summary, our results demonstrate a system of linear and non-linear relationships between the investigated factors and BMI. Moreover, body weight status was not only associated with eating behavior (cognitive restraint and disinhibition), but also with personality factors not inherently related to an eating context (BIS/BAS). Importantly, these relationships differ between men and women.

DSM-5 eating disorders and other specified eating and feeding disorders: is there a meaningful differentiation?

OBJECTIVE

In the DSM-5 diagnostic criteria for eating disorders, two main groups appear, threshold eating disorders (TED; anorexia nervosa, bulimia nervosa, and binge eating disorder), and other specified feeding and eating disorders (OSFED). In addition to calculating prevalence of these two groups, we examined the degree to which they could be differentiated in terms of impairment and risk factors.

METHOD

Adolescent female twins (N = 699) were interviewed with the Eating Disorder Examination on three occasions spanning 12.70-19.84 years of age. Assessments also included self-report measures related to impairment and risk.

RESULTS

Prevalence of DSM-5 ED in this adolescent population was 10.4%; 5.4% for TED and 5% for OSFED. Impairment levels did not distinguish TED and OSFED groups at any wave. Examination of latent risk factors showed TED and OSFED groups to share a common genetic basis; however, largely nonoverlapping unique environmental influences contributed to the two groups. Specific risk factors commonly differentiated the no ED and TED groups, but not OSFED.

DISCUSSION

The findings suggest that TED and OSFED groups cannot be discriminated by prevalence or impairment or genetic risk factors. It is anticipated that OSFED will possess limited clinical utility for adolescents. Future research should examine clinical cases of these two groups in terms of meaningful differences, and a research focus should be maintained on both groups. Further examination of specific environmental risk factors that may attenuate the level of symptoms between the two groups may provide useful information for prevention efforts.

Eating disorder prevention: current evidence-base and future directions

OBJECTIVE

This narrative review sought to (a) characterize prevention programs that have produced reliable, reproducible, and clinically meaningful effects in efficacy trials, (b) discuss effectiveness trials that have tested whether prevention programs produce intervention effects under ecologically valid real-world conditions, (c) discuss dissemination efforts and research on dissemination, and (d) offer suggestions regarding directions for future research in this field.

CONCLUSION

A literature revealed that 6 prevention programs have produced significant reductions in eating disorder symptoms through at least 6-month follow-up and that 2 have significantly reduced future eating disorder onset. Effectiveness trials indicate that 2 prevention programs have produced effects under ecologically valid conditions that are only slightly attenuated. Although there have been few dissemination efforts, evidence suggests that a community participatory approach is most effective. Lastly, it would be useful to develop programs that produce larger and more persistent reductions in eating disorder symptoms and eating disorder onset, focus more on effectiveness trials that confirm that prevention programs produce clinically meaningful effects under real-world conditions, conduct meditational, mechanisms of action, and moderator research that provides stronger support for the intervention theory of prevention programs, and investigate the optimal methods of disseminating and implementing evidence-based prevention programs.

Inpatients with severe anorexia nervosa and their siblings: non-shared experiences and family functioning

OBJECTIVES

The aims of this study were the following: to identify perceptions of patients with anorexia nervosa (AN) and their siblings regarding differential experiences within and external to the family including sibling interactions, parental treatment, relationships with peers and events that are unique to each sibling; (2) to compare how patients and their siblings perceive eating disorder symptoms, parental affection/control, social support and stigma; and (3) to test associations with family functioning for patients with AN and their siblings.

METHOD

A total of 26 patients paired with their siblings were recruited from an Eating Disorder Program and administered standardized instruments measuring different experiences within and external to the family, the impact of eating disorder behaviours, stigma, social support and family functioning.

RESULTS

Patients rated high on the differential experience of jealousy in contrast to their siblings. Patients scored higher than their siblings on eating symptoms, whereas siblings scored higher on social support. The impact of AN on the family, stigma towards the individual and family, and social support accounted for 37% of the variance in family functioning from the sibling perspective after controlling for age and gender. Of these variables, impact of AN on the family made the largest contribution.

DISCUSSION

Family-based and sibling-based interventions that aim to reduce the effects of the illness on the sibling relationship and the family are recommended.

Punishment and reward sensitivity: are naturally occurring clusters in these traits related to eating and weight problems in adolescents?

Little is known about the role of sensitivity to punishment (SP) and reward (SR) in eating problems during adolescence. Therefore, the aim of the present study was to examine the naturally occurring clusters of high and low SP and SR among nonclinical adolescents and the between-cluster differences in various eating problems and weight. A total of 579 adolescents (14-19 years, 39.8% boys) completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ), the Behavioural Inhibition System and Behavioural Activation System scales (BIS/BAS scales), the Dutch Eating Behaviour Questionnaire and the Child Eating Disorder Examination Questionnaire and were weighed and measured. On the basis of the SPSRQ, four clusters were established, interpreted as lowSP × lowSR, lowSP × highSR, highSP × highSR and highSP × lowSR. These were associated with eating problems but not with adjusted body mass index. It seemed that specifically the highSP × highSR cluster outscored the other clusters on eating problems. These results were partly replicated with the BIS/BAS scales, although less significant relations between the clusters and eating problems were found. The implications of the findings in terms of possible risk and protective clusters are discussed.

Australian Twin Registry: 30 years of progress

The Australian Twin Registry (ATR) is a national volunteer resource of twin pairs and higher-order multiples willing to consider participating in health, medical, and scientific research. The vision of the ATR is 'to realize the full potential of research involving twins to improve the health and well-being of all Australians'. The ATR has been funded continuously by the National Health and Medical Council for more than 30 years. Its core functions entail the recruitment and retention of twin members, the maintenance of an up-to-date database containing members' contact details and baseline information, and the promotion and provision of open access to researchers from all institutes in Australia, and their collaborators, in a fair and equitable manner. The ATR is administered by The University of Melbourne, which acts as custodian. Since the late 1970s the ATR has enrolled more than 40,000 twin pairs of all zygosities and facilitated more than 500 studies that have produced at least 700 peer-reviewed publications from classical twin studies, co-twin control studies, within-pair comparisons, twin family studies, longitudinal twin studies, randomized controlled trials, and epigenetics studies, as well as studies of issues specific to twins. New initiatives include: a Health and Life Style Questionnaire; data collection, management, and archiving using a secure online software program (The Ark); and the International Network of Twin Registries. The ATR's expertise and 30 years of experience in providing services to national and international twin studies has made it an important resource for research across a broad range of disciplines.

Neurobiological and psychopathological variables related to emotional instability: a study of their capability to discriminate patients with bulimia nervosa from healthy controls

OBJECTIVE

To analyze the capability of a set of neurobiological and psychopathological variables to discriminate bulimia nervosa (BN) patients from healthy controls.

METHOD

Seventy-five female patients with purging BN and 30 healthy controls were compared for psychopathology (impulsivity, borderline personality traits, depressive symptoms and self-defeating personality traits) and neurobiological parameters reflecting hypothalamic-pituitary-adrenal axis activity (morning serum cortisol before and after dexamethasone) and monoamine activity (24-hour urinary excretion of norepinephrine, serotonin, dopamine, and their main metabolites: 3-methoxy-4-hydroxyphenylglycol, 5-hydroxyindoleacetic acid, and homovanillic acid). Furthermore, the relationships between the 2 sets of variables were compared in the 2 samples.

RESULTS

BN patients displayed higher impulsivity, more severe depressive features, and more borderline and self-defeating personality traits than controls. The 4 psychopathological variables were strongly interrelated in patients, whereas only depressive features correlated with self-defeating personality traits in controls. Patients had lower 24-hour excretion of serotonin and dopamine than controls, as well as lower ability to suppress cortisol. The relations between the biochemical and the psychopathological variables were only significant in the BN patients, but not in the control group. When discriminant analysis methods were applied, patients and controls differed for psychopathology (impulsive behaviors and borderline personality traits) and biological parameters (baseline cortisol and dopamine excretion), but when the variables were analyzed together, the differences in neurobiological parameters appeared as mediated by the psychopathological status.

DISCUSSION

Our results suggest that hypothalamic-pituitary-adrenal axis activity, dopamine activity and other biological parameters are worthy of further study as potential dimensional markers of BN, although they seem to depend on the psychopathological status of the patients, in such a way that the psychopathological items associated with emotional instability (impulsivity and borderline personality traits) seem to be more reliable as clinical markers at the time being.

Approach and avoidance motivation in eating disorders

It has been proposed that approach and avoidance processes may be critically involved in the development and maintenance of eating disorders (EDs), including anorexia nervosa (AN) and bulimia nervosa (BN). The Behavioural Inhibition System and Behavioural Activation System Scales (BIS/BAS) and Appetitive Motivation Scale (AMS) questionnaires were administered to 286 participants: 91 healthy controls (HCs), 121 participants with a current ED, either AN (restrictive and binge purge subtypes), or BN and 74 participants recovered from an ED. Individuals with EDs had higher levels of sensitivity to punishment and lower levels of reward reactivity than controls. Individuals in recovery from an ED scored the same as those in the acute group, with the exception of BAS fun seeking, for which they scored significantly higher than those with restricting AN. Discriminant analysis revealed that HCs were maximally separated from those in the acute and recovered ED groups along a dimension reflecting high punishment sensitivity and low reward sensitivity. Classification analysis demonstrated that ED and HC group membership was predicted from reward and punishment sensitivity measures; however recovered participants tended to be misclassified as ED. This study suggests high punishment sensitivity and low reward reactivity/sensitivity might form a personality cluster associated with the risk of developing an ED.

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.

Age differences in genetic and environmental influences on weight and shape concerns

OBJECTIVE

Previous research has shown important developmental shifts ingenetic and environmental influences for disordered eating. However, little research has examined age differences for weight/shape concerns, two key components of eating disorders. The goal of this study was to investigate these age differences in preadolescent, adolescent, young adult, and mid-adult twins.

METHOD

Participants included 2,618 female twins (ages of 10-41 years) from three large twin registries. Shape and weight concerns were assessed with the Eating Disorders Examination Questionnaire.

RESULTS

Genetic influences were modest in preadolescent twins, but significant from early-adolescence through middle adulthood. Shared environmental factors showed the opposite pattern, with the largest shared environmental contributions occurring in the youngest age group. Nonshared environmental effects remained relatively constant across age.

DISCUSSION

Findings highlight the importance of age differences in genetic and environmental influences. Possible mechanisms include gene x environment interactions and biological changes associated with key developmental stages.

Eating disorders: the current status of molecular genetic research

Anorexia nervosa (AN) and bulimia nervosa (BN) are complex disorders characterized by disordered eating behavior where the patient's attitude towards weight and shape, as well as their perception of body shape, are disturbed. Formal genetic studies on twins and families suggested a substantial genetic influence for AN and BN. Candidate gene studies have initially focused on the serotonergic and other central neurotransmitter systems and on genes involved in body weight regulation. Hardly any of the positive findings achieved in these studies were unequivocally confirmed or substantiated in meta-analyses. This might be due to too small sample sizes and thus low power and/or the genes underlying eating disorders have not yet been analyzed. However, some studies that also used subphenotypes (e.g., restricting type of AN) led to more specific results; however, confirmation is as yet mostly lacking. Systematic genome-wide linkage scans based on families with at least two individuals with an eating disorder (AN or BN) revealed initial linkage regions on chromosomes 1, 3 and 4 (AN) and 10p (BN). Analyses on candidate genes in the chromosome 1 linkage region led to the (as yet unconfirmed) identification of certain variants associated with AN. Genome-wide association studies are under way and will presumably help to identify genes and pathways involved in these eating disorders. The elucidation of the molecular mechanisms underlying eating disorders might improve therapeutic approaches.

Personality and temperament

The assessment of personality and temperament in the context of eating disorders (EDs) poses unique challenges because of the physiological symptoms and sequelae of these illnesses. Four models of the relationship between personality and EDs are presented, along with a discussion of the different methodological designs which can evaluate these models. Current data support the likelihood that neuroticism and perfectionism are risk factors for EDs. Perfectionism and the related obsessive-compulsive personality disorder may also share a common cause with anorexia nervosa. High harm avoidance and low self-directedness also characterize all EDs, though more data are needed to confirm their role as risk factors; importantly however, this combination of traits may diminish one's ability to cope with stressful life events. At the other end of the spectrum, considering impulsivity multidimensionally may be important to understanding the role of this personality trait in EDs, though existing data do not yet allow for conclusions regarding its role as a risk factor versus a consequence of the ED. All of the identified traits that may be risk factors are also exacerbated as a consequence of having, or having had, an ED. Finally, the role of personality disorders in influencing the course and outcome of EDs is still unclear. A fruitful avenue for future research in this area is to utilize personality and temperament to classify individuals in a way that allows for the best chance of identifying genetic loci that confer increased risk for EDs.

The heritability of eating disorders: methods and current findings

Family, twin, and adoption studies of anorexia nervosa (AN), bulimia nervosa (BN), binge-eating disorder (BED), and the proposed purging disorder presentation (PD) have consistently demonstrated that genetic factors contribute to the variance in liability to eating disorders. In addition, endophenotypes and component phenotypes of eating disorders have been evaluated and provide further insight regarding genetic factors influencing eating disorders and eating disorder diagnostic criteria. Many of these phenotypes have demonstrated substantial heritability. This chapter reviews biometrical genetic methods and current findings from family and twin studies that investigate the role of genes and environment in the etiology of eating disorders. We review the methodology used to estimate heritability, the results of these studies, and discuss the implications of this research for the basic conceptualization of eating disorders and the future value of twin modeling in the molecular genetic era.

Reduction of shape and weight concern in young adolescents: a 30-month controlled evaluation of a media literacy program

OBJECTIVE

Recent eating disorder prevention efforts have targeted high-risk females in late adolescence (>15 years). Methodologically rigorous evaluations of prevention programs directed to younger, mixed-sex, universal audiences are largely absent. The primary objective was to evaluate a theoretically informed media literacy program delivered to a mixed-sex, universal, young adolescent audience.

METHOD

Five hundred forty Grade 8 students (mean age 13.62 years, SD 0.37 years) from 4 schools participated with a total of 11 classes receiving the 8-lesson media literacy program (126 girls and 107 boys) and 13 comparison classes receiving their normal school lessons (147 girls and 160 boys). Shape and weight concern (primary outcome variable) and seven additional eating disorder risk factors (e.g., dieting, media internalization) were measured with validated questionnaires at baseline, postprogram, and 6- and 30-month follow-up.

RESULTS

Linear mixed model analyses were conducted using a 2 (group: media literacy program, control) x 3 (time: postprogram, 6-month follow-up, 30-month follow-up) x 2 (sex: girls, boys) mixed within-between design, with baseline entered as a covariate. Main effects for group, favoring the media literacy program, were found for shape and weight concern (effect size [ES] = 0.29), dieting (ES = 0.26), body dissatisfaction (ES = 0.20), ineffectiveness (ES = 0.23), and depression (ES = 0.26).

CONCLUSION

Media literacy can be an effective intervention for reducing shape and weight concern and other eating disorder risk factors long-term in a universal mixed-sex, young adolescent population. More evaluations of methodologically sound prevention programs are required with this demographic.