A Comparison of Personality, Life Events, Comorbidity, and Health in Monozygotic Twins Discordant for Anorexia Nervosa.

Genetic and environmental factors contribute to the etiology of anorexia nervosa (AN). The co-twin control design is one of the most powerful methods available to evaluate environmental factors that could contribute to differences between monozygotic (MZ) twins who are discordant for AN. Using available data from a unique and rare sample of 22 Swedish female MZ pairs discordant for AN, we compared personality, life events, comorbidity, and health factors. Twins with AN had significantly higher perfectionism scores than unaffected co-twins and reported younger ages at first diet than unaffected co-twins who had dieted. Consistent with previous literature, more twins with AN reported gastrointestinal problems than unaffected co-twins. Although not significant due to low statistical power, more unaffected co-twins reported experiencing emotional neglect than twins with AN. Early dieting may be a harbinger of the development of AN or an early symptom. Higher perfectionism may represent a risk factor, sequela, or both. Sibling perception of neglect is noteworthy given the impact of an ill child with AN on family function and wellbeing. The health and wellbeing of siblings should be addressed clinically when one child in the family suffers from AN.

Genetic and environmental components to self-induced vomiting.

OBJECTIVE: We examined the association between the genetic and environmental factors contributing to the liability to having ever engaged in self-induced vomiting (SIV initiation) and the genetic and environmental factors contributing to regular SIV behaviors (weekly or daily) for weight control. METHOD: SIV was assessed in 3,942 women from monozygotic twin pairs and 2,790 women from same-sex dizygotic twin pairs, aged 20-47, from the Swedish Twin study of Adults: Genes and Environment. A causal-contingent-common pathway model assessed the extent to which genetic and environmental factors that influence initiation of SIV also influence regular SIV behaviors. RESULTS: In the best-fit model, genetic and individual-specific environmental factors influenced liability to SIV initiation. The genetic factors influencing regular SIV behaviors were the same as the genetic factors influencing SIV initiation. Additional individual-specific environmental factors that were unrelated to SIV initiation influenced regular SIV behaviors. DISCUSSION: Our findings provide evidence that the underlying liabilities for SIV initiation and regular SIV lie on the same continuum given the degree of overlap in risk between SIV initiation and regular SIV behaviors. Further, the lack of specific genetic factors and the importance of individual-specific environmental factors for regular SIV behaviors highlight the significance of environmental factors in the etiology of eating disorder symptomatology and the non-deterministic nature of genetic factors. Finally, our results suggest that when it comes to preventing individuals from developing regular SIV behavior, intervening at an environmental level is warranted.

The genetics of eating disorders.

Over the past decade, considerable advances have been made in understanding genetic influences on eating pathology. Eating disorders aggregate in families, and twin studies reveal that additive genetic factors account for approximately 40% to 60% of liability to anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Molecular genetics studies have been undertaken to identify alterations in deoxyribonucleic acid sequence and/or gene expression that may be involved in the pathogenesis of disordered eating behaviors, symptoms, and related disorders and to uncover potential genetic variants that may contribute to variability of treatment response. This article provides an in-depth review of the scientific literature on the genetics of AN, BN, and BED including extant studies, emerging hypotheses, future directions, and clinical implications.

Body dissatisfaction in women across the lifespan: results of the UNC-SELF and Gender and Body Image (GABI) studies.

To explore age differences in current and preferred silhouette and body dissatisfaction (current - preferred silhouette discrepancy) in women aged 25-89 years using figural stimuli [range: 1 (very small) to 9 (very large)]. Data were abstracted from two online convenience samples (N = 5868). t-tests with permutation-adjusted p-values examined linear associations between mean silhouette scores (current, preferred, discrepancy score) and age with/without stratification by body mass index (BMI). Modal current silhouette was 5; modal preferred silhouette was 4; mean discrepancy score was 1.8. There was no significant association between current silhouette and age, but a positive linear association between preferred silhouette and age remained after stratification by BMI. A significant inverse linear association of silhouette discrepancy score and age was found only prior to stratification by BMI. Body dissatisfaction exists in women across the adult life span and is influenced by BMI.

Sleep problems are associated with binge eating in women.

OBJECTIVE: We examined the association among current self-reported sleep problems, lifetime binge eating (BE), and current obesity in women from the Swedish Twin study of Adults: Genes and Environment. METHOD: Logistic regression analyses were used to evaluate these associations in 3,790 women aged 20-47 years. RESULTS: BE was reported by 244 (6.4%) women and was positively associated with not getting enough sleep (p < .015), sleeping poorly (p < .001), problems falling asleep (p < .001), feeling sleepy during work or free time (p < .001), and disturbed sleep (p < .001). These same sleep variables, as well as napping and being a night person, were also significantly associated with obesity. The associations between BE and sleep remained after accounting for obesity. DISCUSSION: This investigation offers empirical support for an independent association between sleep problems and BE, which is likely due to complex psychological, biological, neuroendocrine, and metabolic factors.

Effects of reducing the frequency and duration criteria for binge eating on lifetime prevalence of bulimia nervosa and binge eating disorder: implications for DSM-5.

OBJECTIVE: We assessed the impact of reducing the binge eating frequency and duration thresholds on the diagnostic criteria for bulimia nervosa (BN) and binge eating disorder (BED). METHOD: We estimated the lifetime population prevalence of BN and BED in 13,295 female twins from the Swedish Twin study of Adults: Genes and Environment employing a range of frequency and duration thresholds. External validation (risk to cotwin) was used to investigate empirical evidence for an optimal binge eating frequency threshold. RESULTS: The lifetime prevalence estimates of BN and BED increased linearly as the frequency criterion decreased. As the required duration increased, the prevalence of BED decreased slightly. Discontinuity in cotwin risk was observed in BN between at least four times per month and at least five times per month. This model could not be fit for BED. DISCUSSION: The proposed changes to the DSM-5 binge eating frequency and duration criteria would allow for better detection of binge eating pathology without resulting in a markedly higher lifetime prevalence of BN or BED.

Retrospective maternal report of early eating behaviours in anorexia nervosa.

This exploratory study assessed whether maternal recall of childhood feeding and eating practices differed across anorexia nervosa (AN) subtypes. Participants were 325 women from the Genetics of Anorexia Nervosa study whose mothers completed a childhood feeding and eating questionnaire. Multinomial logistic regression analyses were used to predict AN subtype from measures related to childhood eating: (i) infant feeding (breastfed, feeding schedule, age of solid food introduction), (ii) childhood picky eating (picky eating before age 1 year and between ages one and five) and (iii) infant gastrointestinal problems (vomiting and colic). Results revealed no significant differences in retrospective maternal report of childhood feeding and eating practices among AN subtypes.

Effects of a reality TV cosmetic surgery makeover program on eating disordered attitudes and behaviors.

OBJECTIVE: To evaluate the effects of a reality TV cosmetic surgery program on eating disordered attitudes, behaviors, mood, anxiety, and self-esteem. METHOD: Participants (N=147 women) completed baseline surveys and were subsequently randomly assigned to one of two conditions: one in which they watched a reality TV cosmetic surgery program (The Swan) and one in which they watched a reality TV home improvement program (Clean Sweep). Assessments were conducted immediately post-video and two weeks later. RESULTS: Women in the cosmetic surgery program group who reported higher internalization of the thin-ideal at baseline manifested lower self-esteem at posttesting. Among White women, those who watched the cosmetic surgery program reported greater perceptions of media pressures to be thin and stronger endorsement of their ability to control their body's appearance after watching the video. These differences persisted over a two-week follow-up period. DISCUSSION: Reality TV cosmetic surgery makeover programs may contribute to eating disordered attitudes and behaviors among young women, particularly those who have internalized the thin body-ideal. These findings seem to be especially applicable for White women; however, they should be further investigated with more diverse and international samples.

Ultraviolet- and short-wavelength cone contributions alter the early components of the ERG of young zebrafish.

The electroretinogram (ERG) is a commonly used measure to examine retinal processing in both basic and clinical research. The purpose of this study was to determine the retinal mechanisms responsible for the developmental differences found in the zebrafish ERG waveform. The ERG of young zebrafish possesses a voltage-negative response to ultraviolet- and short-wavelength stimuli, but not to middle- and long-wavelength stimuli; the ERG of adult zebrafish does not possess this response component. ERGs were obtained from young zebrafish before and after the introduction of either aspartate, or a combination of APB (DL-2-amino-4-phosphonobutyric acid) and PDA (cis-2,3-piperidinedicarboxylic acid) in order to suppress the responses of various types of retinal neurons. Log irradiance versus response amplitude functions of the ERG response to 200-ms stimuli of various wavelengths at various times following stimulus onset (70 and 120 ms) was derived as well as spectral sensitivity. Aspartate eliminated all voltage-positive responses regardless of stimulus wavelength; irradiance-response functions following aspartate were similar to the early responses of young control fish to ultraviolet- and short-wavelength stimuli. APB + PDA produced similar but not identical results as aspartate, suggesting that the combination of these agents does not completely eliminate all post-receptoral contributions to the ERG. Spectral sensitivity functions derived from aspartate-exposed subjects at various time measurements were dominated by contributions from ultraviolet- and short-wavelength-sensitive cone types. These wavelength-dependent ERG responses are similar to those found in humans with enhanced S-cone syndrome. Finally, ERG waveform differences across stimulus wavelength suggest that the circuitry of ultraviolet- and short-wavelength cone types is different to that of middle- and long-wavelength cone types in young zebrafish.

Assessment of gene expression in peripheral blood using RNAseq before and after weight restoration in anorexia nervosa.

We examined gene expression in the blood of six females with anorexia nervosa (AN) before and after weight restoration using RNAseq. AN cases (aged 19-39) completed clinical assessments and had blood drawn for RNA at hospital admission (T1,<~75% ideal body weight, IBW) and again at discharge (T2,≥ ~ 85% IBW). To examine the relationship between weight restoration and differential gene expression, normalized gene expression levels were analyzed using a paired design. We found 564 genes whose expression was nominally significantly different following weight restoration (p<0.01, 231 increased and 333 decreased). With a more stringent significance threshold (false discovery rate q<0.05), 67 genes met criteria for differential expression. Of the top 20 genes, CYP11A1, C16orf11, LINC00235, and CPA3 were down-regulated more than two-fold after weight restoration while multiple olfactory receptor genes (OR52J3, OR51L1, OR51A4, and OR51A2) were up-regulated more than two-fold after weight restoration. Pathway analysis revealed up-regulation of two broad pathways with largely overlapping genes, one related to protein secretion and signaling and the other associated with defense response to bacterial regulation. Although results are preliminary secondary to a small sample size, these data provide initial evidence of transcriptional alterations during weight restoration in AN.

A behavioral-genetic investigation of bulimia nervosa and its relationship with alcohol use disorder.

Bulimia nervosa (BN) and alcohol use disorder (AUD) frequently co-occur and may share genetic factors; however, the nature of their association is not fully understood. We assessed the extent to which the same genetic and environmental factors contribute to liability to BN and AUD. A bivariate structural equation model using a Cholesky decomposition was fit to data from 7241 women who participated in the Swedish Twin study of Adults: Genes and Environment. The proportion of variance accounted for by genetic and environmental factors for BN and AUD and the genetic and environmental correlations between these disorders were estimated. In the best-fitting model, the heritability estimates were 0.55 (95% CI: 0.37; 0.70) for BN and 0.62 (95% CI: 0.54; 0.70) for AUD. Unique environmental factors accounted for the remainder of variance for BN. The genetic correlation between BN and AUD was 0.23 (95% CI: 0.01; 0.44), and the correlation between the unique environmental factors for the two disorders was 0.35 (95% CI: 0.08; 0.61), suggesting moderate overlap in these factors. The findings from this investigation provide additional support that some of the same genetic factors may influence liability to both BN and AUD.

Binge eating, body mass index, and gastrointestinal symptoms.

OBJECTIVE: Symptoms of both gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS) are frequently reported by individuals who binge eat. Higher body mass index (BMI) has also been associated with these disorders and with binge eating (BE). However, it is unknown whether BE influences GERD/IBS and how BMI might affect these associations. Thus, we examined the potential associations among BE, GERD, IBS, and BMI. METHODS: Participants were from the Swedish Twin study of Adults: Genes and Environment (STAGE) and provided information on disordered eating behavior, BMI, gastrointestinal (GI) disorders, and commonly comorbid psychiatric and somatic illnesses. Key features of GERD and IBS were identified to create modified definitions of both disorders that were used as primary outcome variables. Logistic regression models were applied to determine the association between BE and each GERD/IBS both independently and in the context of BMI and other commonly comorbid psychiatric and somatic morbidities. RESULTS: Prevalence estimates for GERD and IBS were higher among women than men (all p-values<.001). Only the association between BE and IBS was significant in both men and women after adjustment for BMI and the psychiatric/somatic morbidities. CONCLUSION: BE appears to be an important consideration in the presence of IBS symptoms in both men and women, even when considering the impact of BMI and other commonly comorbid conditions. This association underscores the importance of routine assessment of BE in patients presenting with IBS to effectively manage the concurrent presentation of these problems.

An evaluation of the reliability and construct validity of eating disorder measures in white and black women.

Most measures of eating disorder symptoms and risk factors were developed in predominantly White female samples. Yet eating disorders affect individuals of all racial and ethnic backgrounds. Black women appear more vulnerable to certain forms of eating pathology, such as binge eating, and less susceptible to other eating disorder symptoms and risk factors, such as body dissatisfaction, compared with their White peers. Despite concern that extant measures do not adequately assess eating concerns among Black women, the construct validity of scores on most of these measures has not been adequately examined within this population. This study included 2,208 Black and White women who completed the following: the Binge Eating Scale (BES), the Eating Disorder Diagnostic Scale (EDDS), the Eating Attitudes Test-26 (EAT-26), the Eating Disorder Inventory Body Dissatisfaction and Drive for Thinness subscales, the Bulimia Test-Revised (BULIT-R), the Multidimensional Body-Self Relations Questionnaire-Appearance Evaluation subscale (MBSRQ-AE), and the Objectified Body Consciousness Scale (OBCS). Most measures yielded internally consistent scores in both races. Confirmatory factor analyses indicated that loadings for some measures, including the EAT-26 and EDDS, were not invariant across groups and thus do not assess equivalent constructs in White and Black women. However, others, including the BULIT-R, BES, OBCS, and MBSRQ-AE, exhibited factorial invariance in both races. Results suggest scores are likely not equivalent across races for several popular measures of eating disorder symptoms and risk factors. Thus, it is recommended that researchers and clinicians obtain additional information regarding racial/cultural factors when using these instruments with Black women.

CBT4BN versus CBTF2F: comparison of online versus face-to-face treatment for bulimia nervosa.

Cognitive-behavioral therapy (CBT) is currently the "gold standard" for treatment of bulimia nervosa (BN), and is effective for approximately 40-60% of individuals receiving treatment; however, the majority of individuals in need of care do not have access to CBT. New strategies for service delivery of CBT and for maximizing maintenance of treatment benefits are critical for improving our ability to treat BN. This clinical trial is comparing an Internet-based version of CBT (CBT4BN) in which group intervention is conducted via therapeutic chat group with traditional group CBT (CBTF2F) for BN conducted via face-to-face therapy group. The purpose of the trial is to determine whether manualized CBT delivered via the Internet is not inferior to the gold standard of manualized group CBT. In this two-site randomized controlled trial, powered for non-inferiority analyses, 180 individuals with BN are being randomized to either CBT4BN or CBTF2F. We hypothesize that CBT4BN will not be inferior to CBTF2F and that participants will value the convenience of an online intervention. If not inferior, CBT4BN may be a cost-effective approach to service delivery for individuals requiring treatment for BN.

Schizophrenia genetics: where next?

The purpose of this invited review is to summarize the state of genetic research into the etiology of schizophrenia (SCZ) and to consider options for progress. The fundamental uncertainty in SCZ genetics has always been the nature of the beast, the underlying genetic architecture. If this were known, studies using the appropriate technologies and sample sizes could be designed with an excellent chance of producing high-confidence results. Until recently, few pertinent data were available, and the field necessarily relied on speculation. However, for the first time in the complex and frustrating history of inquiry into the genetics of SCZ, we now have empirical data about the genetic basis of SCZ that implicate specific loci and that can be used to plan the next steps forward.

Preventing weight gain in first year college students: an online intervention to prevent the "freshman fifteen".

The transition to college has been identified as a critical period for increases in overweight status. Overweight college students are at-risk of becoming obese adults, and, thus prevention efforts targeting college age individuals are key to reducing adult obesity rates. The current study evaluated an Internet intervention with first year college students (N=170) randomly assigned to one of four treatment conditions: 1) no treatment, 2) 6-week online intervention 3) 6-week weight and caloric feedback only (via email), and 4) 6-week combined feedback and online intervention. The combined intervention group had lower BMIs at post-testing than the other three groups. This study demonstrated the effectiveness and feasibility of an online intervention to prevent weight gain among college students.