The effects of puberty on genetic risk for disordered eating: evidence for a sex difference

Interactions Between Genetic, Prenatal Substance Use, Puberty, and Parenting are Less Important for Understanding Adolescents' Internalizing, Externalizing, and Substance Use than Developmental Cascades in Multifactorial Models

This study tested interactions among puberty-related genetic risk, prenatal substance use, harsh discipline, and pubertal timing for the severity and directionality (i.e., differentiation) of externalizing and internalizing problems and adolescent substance use. This is a companion paper to Marceau et al. (2021) which examined the same influences in developmental cascade models. Data were from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort (n = 4504 White boys, n = 4287 White girls assessed from the prenatal period through 18.5 years). We hypothesized generally that later predictors would strengthen the influence of puberty-related genetic risk, prenatal substance use exposure, and pubertal risk on psychopathology and substance use (two-way interactions), and that later predictors would strengthen the interactions of earlier influences on psychopathology and substance use (three-way interactions). Interactions were sparse. Although all fourteen interactions showed that later influences can exacerbate or trigger the effects of earlier ones, they often were not in the expected direction. The most robust moderator was parental discipline, and differing and synergistic effects of biological and socially-relevant aspects of puberty were found. In all, the influences examined here operate more robustly in developmental cascades than in interaction with each other for the development of psychopathology and transitions to substance use.

"Good food equals good health": a focus group study of adolescent boys' perceptions of eating and weight

BACKGROUND

Disordered eating refers to unhealthy, sometimes excessive eating including so-called compensatory behaviours such as extreme dieting or voluntary vomiting. Between 24% and 30% of adolescent boys are suggested to engage in disordered eating, making it a significant public health issue. However, current instruments for assessing disordered eating among adolescents have been primarily developed and validated for girls and women, which may make for flawed assessment of boys. The aim of this study is to shed light on adolescent boys' perceptions of eating, weight, and food intake to better understand their perspectives in service of disordered eating research.

METHODS

This exploratory study was conducted from May to November 2022 using focus groups with a total of 39 adolescent boys (aged 12-19 years) who attended 7th to 12th grade in one of four schools in Southern Sweden. In addition, participants completed a form with questions on background demographics and eating habits. The transcripts of the focus group discussions were analysed using thematic analysis.

RESULTS

The quantitative data showed that around one third of the adolescent boys were overweight or obese. They ate at least one meal per day with the family and ate healthy food about five days per week and unhealthy food about three. Analysis of the qualitative data yielded six themes: The intertwined relationship between food and one's health, "Don't worry, food makes you happy," "To be hungry or not. That is the question," Boys DO care about appearances, Dieting and weight gain, and Disordered eating is a tricky matter.

CONCLUSION

Adolescent boys appeared to have a good understanding of food and healthy eating. They also experienced body positivity and seemed to have only minor issues regarding their weight. The primarily pathological perspective used to measure disordered eating among girls seems in need of revision to adhere to boys' thoughts and ideas regarding eating and weight.

Estrogen moderation of genetic influences on eating disorder symptoms during gonadarche in girls: Specific effects on binge eating

The heritability of eating disorder (ED) symptoms increases dramatically across gonadarche in girls. Past studies suggest these developmental differences could be due to pubertal activation of estrogen, but findings have been limited to only one ED symptom (i.e., binge eating). The current study examined whether estrogen contributes to gonadarcheal differences in genetic influences on overall levels of ED symptoms as well as key cognitive symptoms (i.e., weight/shape concerns) that are present across all EDs and are early risk factors for eating pathology. Given that binge eating frequently co-occurs with all of these symptoms, analyses also examined whether estrogen effects exist for overall levels of ED symptoms and body weight/shape concerns after accounting for the known effects of estrogen on genetic risk for binge eating. Participants included 964 female twins (ages 8-16) from the Michigan State University Twin Registry. Overall levels of ED symptoms were assessed with the Minnesota Eating Behavior Survey (MEBS) total score. Weight/shape concerns were assessed with a latent factor modeled using subscales from the MEBS and the Eating Disorder Examination Questionnaire. Estradiol levels were assessed with saliva samples. Twin moderation models were used to examine whether genetic influences on overall levels of ED symptoms and weight/shape concerns differed significantly across estradiol levels. Although initial models suggested modest differences in genetic influences on overall levels of ED symptoms across estradiol levels, these effects were eliminated when binge eating was accounted for in the models. In addition, weight/shape concerns did not show significant moderation of genetic influences by estradiol in models with or without binge eating. Taken together, results are significant in suggesting that individual differences in estradiol levels during gonadarche have a unique and specific impact on genetic risk for binge eating, while other etiologic factors must contribute to increased heritability of cognitive ED symptoms during this key developmental period in girls.

The impact of genetic risk for schizophrenia on eating disorder clinical presentations

A growing body of literature recognizes associations between eating disorders (EDs) and schizophrenia and suggests that familial liability to schizophrenia in individuals with anorexia nervosa (AN) reveals distinct patterns of clinical outcomes. To further investigate the influence of schizophrenia genetic liability among individuals with EDs, we evaluated the associations between schizophrenia polygenic risk scores (PRS) and clinical presentations of individuals with EDs including their overall health condition and ED-related symptoms. Using data from two previous studies of the genetics of EDs comprising 3,573 Anorexia Nervosa Genetics Initiative (ANGI) cases and 696 Binge Eating Genetics Initiative (BEGIN) cases born after 1973 and linked to the Swedish National Patient Register, we examined the association of schizophrenia PRS on ED clinical features, psychiatric comorbidities, and somatic and mental health burden. Among ANGI cases, higher schizophrenia PRS was statistically significantly associated with higher risk of major depressive disorder (MDD) measured by hazard ratio (HR) with 95% confidence interval (CI) (HR [95% CI]: 1.07 [1.02, 1.13]) and substance abuse disorder (SUD) (HR [95% CI]: 1.14 [1.03, 1.25]) after applying multiple testing correction. Additionally, higher schizophrenia PRS was associated with decreased clinical impairment assessment scores (-0.56, 95% CI: [-1.04, -0.08]) at the conventional significance level (p < 0.05). Further, in BEGIN cases, higher schizophrenia PRS was statistically significantly associated with earlier age at first ED symptom (-0.35 year, 95% CI: [-0.64, -0.06]), higher ED symptom scores (0.16, 95% CI: [0.04, 0.29]), higher risk of MDD (HR [95% CI]: 1.18 [1.04, 1.34]) and SUD (HR [95% CI]: 1.36 [1.07, 1.73]). Similar, but attenuated, patterns held in the subgroup of exclusively AN vs other eating disorder (OED) cases. These results suggest a similar pattern of influence of schizophrenia PRS for AN and OED cases in terms of psychiatric comorbidities, but a different pattern in terms of ED-related clinical features. The disparity of the effect of schizophrenia PRS on AN vs OED merits further investigation.

Family-based treatment takes longer for adolescents with mental health comorbidities: findings from a community mental health service

Children and adolescents diagnosed with an eating disorder often meet the diagnosis of another mental health disorder. In addition to eating disorders, individuals with comorbid disorders have higher suicide rates and more severe and chronic eating disorder symptoms. The present research aimed to investigate the influence of comorbid conditions on the treatment outcomes of children and adolescents that attended a public community mental health service. It was hypothesised that the patients with comorbidities would have a more extended treatment duration, slower rates of weight restoration, more hospital admissions for medical compromise, and poorer functioning than those without comorbidities. Data from 78 past patients at the Eating Disorder Program in Queensland, Australia, were analysed. Patients with comorbidities demonstrated similar recovery rates to those without comorbidities. However, those with comorbid conditions had longer episodes of treatment. The study's results support using Family Based Treatment for patients with and without comorbidities. The implications of the findings for public mental health services and directions for future research are discussed.

A scoping literature review of the associations between highly visual social media use and eating disorders and disordered eating: a changing landscape

BACKGROUND

Although the etiology of eating disorders (ED) and disorder eating (DE) is multifactorial, exposure to highly visual social media (HVSM) may be an important contributor to the onset or worsening of DE and ED symptoms. We aim to understand HVSM use, ED, and DE with a particular focus on gender differences, as well as details of engagement on "selfies" in adolescents and young adults (AYA) through a scoping review of the literature.

METHODS

We conducted a literature search in Psycho ED, PubMed, MEDLINE of articles, including participants with DE/ED and users of HVSM, focused on AYA. Studies in which the study population did not include AYA, the SM platforms used did not include HVSM platforms, and the methodology to assess ED/HVSM use was not robust were excluded.

RESULTS

We found a strong relationship between HVSM and ED and DE with existing gender differences related to the nature of engagement and preference of content. The literature also shows effects of the specific mechanisms of use of these platforms involving "selfie" preparation and posting. Existing research is limited and consists of mostly cross-sectional studies with no uniform methodology and with participant populations that are not well-defined.

CONCLUSIONS

The use of unregulated and profit-driven SM platforms can increase risk for ED. To use these HVSM platforms for positive influence, there is a need to have more transparency, and involvement of clinicians, researchers, and educators.

PUBLIC SIGNIFICANCE

Due to HVSM's popularity among the AYA population, it is important to identify its effects on the development of DE and ED, as well as recognize any gender differences. Clinicians, parents, and other adults working with youth should be aware of HVSM's impact on DE/ED, as described in this review.

Risk factors for anorexia nervosa: A population-based investigation of sex differences in polygenic risk and early life exposures

OBJECTIVE

To examine sex differences in risk factors for anorexia nervosa (AN).

METHOD

This population-based study involved 44,743 individuals (6,239 AN cases including 5,818 females and 421 males, and 38,504 controls including 18,818 females and 19,686 males) born in Denmark between May 1981 and December 2009. Follow-up began on the individual's sixth birthday and ended at AN diagnosis, emigration, death, or December 31, 2016, whichever occurred first. Exposures included socioeconomic status (SES), pregnancy, birth, and early childhood factors based on data from Danish registers, and psychiatric and metabolic polygenic risk scores (PRS) based on genetic data. Hazard ratios were estimated using weighted Cox proportional hazards models stratified by sex (assigned at birth), with AN diagnosis as the outcome.

RESULTS

The effects of early life exposures and PRS on AN risk were comparable between females and males. Although we observed some differences in the magnitude and direction of effects, there were no significant interactions between sex and SES, pregnancy, birth, or early childhood exposures. The effects of most PRS on AN risk were highly similar between the sexes. We observed significant sex-specific effects of parental psychiatric history and body mass index PRS, though these effects did not survive corrections for multiple comparisons.

CONCLUSIONS

Risk factors for AN are comparable between females and males. Collaboration across countries with large registers is needed to further investigate sex-specific effects of genetic, biological, and environmental exposures on AN risk, including exposures in later childhood and adolescence as well as the additive effects of exposures.

PUBLIC SIGNIFICANCE

Sex differences in the prevalence and clinical presentation of AN warrant examination of sex-specific risk factors. This population-based study indicates that the effects of polygenic risk and early life exposures on AN risk are comparable between females and males. Collaboration between countries with large registers is needed to further investigate sex-specific AN risk factors and improve early identification of AN.

Predicting eating disorder and anxiety symptoms using disorder-specific and transdiagnostic polygenic scores for anorexia nervosa and obsessive-compulsive disorder

BACKGROUND

Clinical, epidemiological, and genetic findings support an overlap between eating disorders, obsessive-compulsive disorder (OCD), and anxiety symptoms. However, little research has examined the role of genetics in the expression of underlying phenotypes. We investigated whether the anorexia nervosa (AN), OCD, or AN/OCD transdiagnostic polygenic scores (PGS) predict eating disorder, OCD, and anxiety symptoms in a large developmental cohort in a sex-specific manner.

METHODS

Using summary statistics from Psychiatric Genomics Consortium AN and OCD genome-wide association studies, we conducted an AN/OCD transdiagnostic genome-wide association meta-analysis. We then calculated AN, OCD, and AN/OCD PGS in participants from the Avon Longitudinal Study of Parents and Children to predict eating disorder, OCD, and anxiety symptoms, stratified by sex (combined N = 3212-5369 per phenotype).

RESULTS

The PGS prediction of eating disorder, OCD, and anxiety phenotypes differed between sexes, although effect sizes were small. AN and AN/OCD PGS played a more prominent role in predicting eating disorder and anxiety risk than OCD PGS, especially in girls. AN/OCD PGS provided a small boost over AN PGS in the prediction of some anxiety symptoms. All three PGS predicted higher compulsive exercise across different developmental timepoints [β = 0.03 (s.e. = 0.01) for AN and AN/OCD PGS at age 14; β = 0.05 (s.e. = 0.02) for OCD PGS at age 16] in girls.

CONCLUSIONS

Compulsive exercise may have a transdiagnostic genetic etiology, and AN genetic risk may play a role in the presence of anxiety symptoms. Converging with prior twin literature, our results also suggest that some of the contribution of genetic risk may be sex-specific.

Prevalence, predictors, and treatment of eating disorders in children: a national study

BACKGROUND

Although the prevalence rates of preadolescent eating disorders (EDs) are on the rise, considerably less is known about the correlates and treatment of EDs in this age group. Clarifying the epidemiology of EDs in preadolescent children is a necessary first step to understand the nature and scope of this problem in this age group.

METHODS

Analysis of data collected in the ABCD Study release 2.0.1. The ABCD cohort was a population-based sample that consisted of 11 721 children ages 9-10 years. Measures included reports of a lifetime and current mental disorders determined using a diagnostic interview for DSM-5 disorders, sociodemographic factors, and psychiatric treatment utilization.

RESULTS

The lifetime prevalence of EDs was 0.95%. Being Black, multiracial, having unmarried parents, and family economic insecurity were significant predictors for developing an ED. Among psychiatric conditions, the major depressive disorder was most robustly associated with EDs in both cross-sectional and temporal analyses. Only 47.40% of children who had a lifetime ED received some type of psychiatric treatment. EDs were not a significant predictor of psychiatric treatment utilization after accounting for sex, sexual orientation, parent marital status, economic insecurity, and all other psychiatric diagnoses.

CONCLUSIONS

Despite increasing prevalence rates of preadolescent EDs, the current findings suggest that the majority of children with these disorders remain untreated. Devoting increased attention and resources to reaching families of children with EDs with the least means for receiving care, and screening for EDs in children with depression, may be important steps for reducing this unmet need.

A Gender-Based Point of View in Pediatric Neurology

While the significance of gender has only recently been recognized, gender assigned at birth has long been understood to have a significant influence on a number of illnesses. Due to the paucity of data in this regard in pediatrics, the purpose of this narrative review is to frame the most recent knowledge about the role of gender assigned at birth in the neurological development and neuropsychiatric disorders among young people. Literature analysis showed that gender disparities exist in neurologic and neuropsychiatric disorders among the pediatric population and supported the fact that new guidelines should take this into account. However, there is an urgent need for specific studies focused on gender role among children and adolescents in order to better understand how this can relate to diagnosis, development and treatment of different neurologic and neuropsychiatric diseases. Moreover, further efforts should be directed to identify unique risks linked to gender disorders and gender dysphoria as well as taking into account a gender point of view when approaching a pediatric patient.

Associations Between Attention Deficit Hyperactivity Disorder Symptom Dimensions and Disordered Eating Symptoms in Adolescence: A Population-Based Twin Study

Although bivariate associations between attention-deficit/hyperactivity disorder (ADHD) and eating disorders in adolescent girls and boys have been previously identified, the mechanistic link underlying the symptom-level associations remains unclear. We evaluated shared genetic and environmental influences on ADHD symptoms and disordered eating in 819 female and 756 male twins from the Swedish TCHAD cohort using bivariate models. Common additive genetic and unique environmental effects accounted for majority of ADHD and disordered eating associations in a differential manner. For girls, the strongest genetic correlation was observed for cognitive/inattention problems-bulimia (0.54), with genetic factors accounting for 67% of the phenotypic correlation. For boys, the strongest genetic correlations were observed for conduct problems-bulimia and hyperactivity-bulimia (~ 0.54), accounting for 83% and 95% of the phenotypic correlation, respectively. As per our findings, the risk of comorbidity and shared genetics highlights the need for preventative measures and specialized treatment for ADHD and disordered eating in both sexes.

Practical Considerations for Using the Eating Disorder Examination Interview with Adolescents

Approximately 35 years after its initial publication, the Eating Disorder Examination (EDE) remains one of the most widely used semi-structured interviews for assessing eating disorder diagnoses and symptomatology. Although the interview provides certain advantages over other common measurement approaches (ie, questionnaires), there are particular considerations regarding the EDE that warrant attention, including in its use with adolescents. The aims of this paper are therefore to: 1) provide a brief overview of the interview itself, as well as a description of its origin and underlying conceptual framework; 2) describe relevant factors for administering the interview with adolescents; 3) review potential limitations regarding use of the EDE with adolescents; 4) address considerations for using the EDE with pertinent subpopulations of adolescents who may experience distinct eating disorder symptoms and/or risk factors; and 5) discuss the integration of self-report questionnaires with the EDE. Advantages of using the EDE include the ability for interviewers to clarify complex concepts and mitigate inattentive responding, enhanced orientation to the interview timeframe to improve recall, increased diagnostic accuracy compared to questionnaires, and accounting for potentially salient external factors (eg, food/eating rules imposed by a parent/guardian). Limitations include more extensive training requirements, greater assessment burden, variable psychometric performance across subgroups, lack of items evaluating muscularity-oriented symptoms and avoidant/restrictive food intake disorder diagnostic criteria, and lack of explicit consideration for salient risk factors other than weight and shape concerns (eg, food insecurity).

Disadvantage and disordered eating in boys: Examining phenotypic and genotype × environment associations across development

Socioeconomic disadvantage may be a significant risk factor for disordered eating, particularly for individuals with underlying genetic risk. However, little to nothing is known about the impact of disadvantage on disordered eating in boys during the critical developmental risk period. Crucially, risk models developed for girls may not necessarily apply to boys, as boys show different developmental patterns of disordered eating risk (i.e., earlier activation of genetic influences during adrenarche, an early stage of puberty). This is the first study to examine phenotypic and Genotype × Environment (G × E) effects of disadvantage in boys. Analyses examined 3,484 male twins ages 8-17 (Mage = 12.27, SD = 2.96) from the Michigan State University Twin Registry. Disordered eating (e.g., body dissatisfaction, binge eating) was measured using the parent-report Michigan Twins Project Eating Disorder Survey. Neighborhood disadvantage was measured using a census-tract level Area Deprivation Index, and family socioeconomic status was determined from parental income and education. Adrenarche status was determined using multiple indicators, including age and Pubertal Development Scale scores. G × E models suggested that genetic influences on disordered eating were activated earlier for boys experiencing familial or neighborhood disadvantage, with substantial genetic influences in early adrenarche, when genetic influences were low in more advantaged boys. Phenotypically, both neighborhood and familial disadvantage were associated with greater disordered eating for boys in late adrenarche, which could indicate a lasting impact of earlier activation of genetic influences on later risk. Results highlight disadvantage as a novel risk factor for disordered eating in boys, particularly those with genetic vulnerabilities. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

What next for eating disorder genetics? Replacing myths with facts to sharpen our understanding

Substantial progress has been made in the understanding of anorexia nervosa (AN) and eating disorder (ED) genetics through the efforts of large-scale collaborative consortia, yielding the first genome-wide significant loci, AN-associated genes, and insights into metabo-psychiatric underpinnings of the disorders. However, the translatability, generalizability, and reach of these insights are hampered by an overly narrow focus in our research. In particular, stereotypes, myths, assumptions and misconceptions have resulted in incomplete or incorrect understandings of ED presentations and trajectories, and exclusion of certain patient groups from our studies. In this review, we aim to counteract these historical imbalances. Taking as our starting point the Academy for Eating Disorders (AED) Truth #5 "Eating disorders affect people of all genders, ages, races, ethnicities, body shapes and weights, sexual orientations, and socioeconomic statuses", we discuss what we do and do not know about the genetic underpinnings of EDs among people in each of these groups, and suggest strategies to design more inclusive studies. In the second half of our review, we outline broad strategic goals whereby ED researchers can expand the diversity, insights, and clinical translatability of their studies.

Adolescent overeating and binge eating behavior in relation to subsequent cardiometabolic risk outcomes: a prospective cohort study

BACKGROUND

Binge eating disorder is bidirectionally associated with obesity and with metabolic syndrome. It is less clear whether overeating and binge eating, or overeating with loss of control, also predicts metabolic risk, and if so, whether these associations are solely attributable to greater weight. The goal of this study was to examine longitudinal associations of overeating and binge eating behavior with cardiometabolic risk markers in adolescence.

METHODS

Adolescents (n = 619) in the Project Viva research study self-reported overeating and binge eating behavior in early adolescence (median 12.9 years, "baseline"). In late adolescence (median 17.4 years, "follow-up"), we assessed outcomes of adiposity and blood pressure, and in a subset of participants (n = 270-424), biomarkers of dyslipidemia, insulin resistance, liver dysfunction, inflammation, and adipokine homeostasis. We conducted multivariable linear regression analyses adjusted for socio-demographics and prenatal obesogenic exposures, and additionally for baseline body mass index (BMI) z-score.

RESULTS

At baseline, 58 (9%) participants reported overeating behavior, and of those, 24 (41%) had binge eating behavior (e.g., overeating accompanied by loss of control). In adjusted models, adolescents with overeating had higher adiposity at follow-up ~ 5 years later (e.g., % body fat 4.03; 95% confidence interval (CI) 1.76, 6.31) than those not reporting overeating behavior; additional adjustment for baseline BMI z-score attenuated associations generally except for % body fat (2.95; 95% CI 1.03, 4.87). Overeating behavior was also associated with higher inflammation and greater adipokine dysfunction, remaining positively associated with interleukin-6 (IL-6) (log-transformed β = 0.42 pg/mL; 95% CI 0.12, 0.73) and negatively with adiponectin (log-transformed β = -0.28 ug/mL; 95% CI - 0.47, - 0.08) even after adjusting for baseline BMI z-score. Overeating behavior was not consistently associated with other outcomes. Adolescents reporting binge eating behavior generally had the greatest adiposity, (e.g., % body fat 5.00; 95% CI 1.74, 8.25) as compared to those without overeating.

CONCLUSIONS

Adolescents reporting overeating and binge eating behavior had higher adiposity and poorer inflammatory and adipokine profiles, but no difference in other outcomes, than adolescents who did not endorse these behaviors. These associations were only partially accounted for by higher baseline BMI z-score. These differences may signal increased risk for future cardiovascular disease.

Exploring the possibility of parents' broad internalizing phenotype acting through passive gene-environment correlations on daughters' disordered eating

Twin studies demonstrate significant environmental influences and a lack of genetic effects on disordered eating before puberty in girls. However, genetic factors could act indirectly through passive gene-environment correlations (rGE; correlations between parents' genes and an environment shaped by those genes) that inflate environmental (but not genetic) estimates. The only study to explore passive rGE did not find significant effects, but the full range of parental phenotypes (e.g., internalizing symptoms) that could impact daughters' disordered eating was not examined. We addressed this gap by exploring whether parents' internalizing symptoms (e.g., anxiety, depressive symptoms) contribute to daughters' eating pathology through passive rGE. Participants were female twin pairs (aged 8-14 years; M = 10.44) in pre-early puberty and their biological parents (n = 279 families) from the Michigan State University Twin Registry. Nuclear twin family models explored passive rGE for parents' internalizing traits/symptoms and twins' overall eating disorder symptoms. No evidence for passive rGE was found. Instead, environmental factors that create similarities between co-twins (but not with their parents) and unique environmental factors were important. In pre-early puberty, genetic factors do not influence daughters' disordered eating, even indirectly through passive rGE. Future research should explore sibling-specific and unique environmental factors during this critical developmental period.

The impact of anorexia nervosa and BMI polygenic risk on childhood growth: A 20-year longitudinal population-based study

Growth deviating from the norm during childhood has been associated with anorexia nervosa (AN) and obesity later in life. In this study, we examined whether polygenic scores (PGSs) for AN and BMI are associated with growth trajectories spanning the first two decades of life. AN PGSs and BMI PGSs were calculated for participants of the Avon Longitudinal Study of Parents and Children (ALSPAC; n = 8,654). Using generalized (mixed) linear models, we associated PGSs with trajectories of weight, height, body mass index (BMI), fat mass index (FMI), lean mass index (LMI), and bone mineral density (BMD). Female participants with AN PGSs one standard deviation (SD) higher had, on average, 0.004% slower growth in BMI between the ages 6.5 and 24 years and a 0.4% slower gain in BMD between the ages 10 and 24 years. Higher BMI PGSs were associated with faster growth for BMI, FMI, LMI, BMD, and weight trajectories in both sexes throughout childhood. Female participants with both a high AN PGS and a low BMI PGS showed slower growth compared to those with both a low AN PGS and a low BMI PGS. We conclude that AN PGSs and BMI PGSs have detectable sex-specific effects on growth trajectories. Female participants with a high AN PGS and low BMI PGS likely constitute a high-risk group for AN, as their growth was slower compared to their peers with high PGSs on both traits. Further research is needed to better understand how the AN PGS and the BMI PGS co-influence growth during childhood and whether a high BMI PGS can mitigate the effects of a high AN PGS.

A Network Analysis Investigation of Disordered Eating Across Demographic and Developmental Subpopulations Using a National Epidemiological Sample of High School Students

Disordered eating (DE) poses a large societal burden, yet limited research has examined DE from a developmental epidemiological perspective. It is important to consider how demographics influence DE symptoms to inform prevention and early intervention programs across diverse subpopulations. Therefore, we conducted network analyses using a large nationally representative epidemiological sample of high school students (Youth Risk Behavior Survey, United States; n = 59,582) to identify the most important symptoms and symptom relationships among six DE behaviors. We compared networks by sex, grade, and race to identify differences in symptom networks. Dieting for weight loss was highly central across networks. Networks significantly differed across sex, grade, and race. Our results suggest that dieting for weight loss may be an early intervention target for eating disorders, regardless of demographic and developmental factors. In addition, sex, race, and age should be accounted for when researching and developing prevention programs for DE and eating disorders. Public health officials, as well as mental health professionals, should present a more balanced message about dieting and weight loss to high school students to prevent the detrimental impact of DE on physical and mental health. Notably, this study is the first large, nationwide epidemiological sample using DE symptoms in network analysis.

Temperament and psychopathology in early childhood predict body dissatisfaction and eating disorder symptoms in adolescence

Eating disorders (ED) are highly impairing and dangerous conditions that typically onset in adolescence. However, very few prospective studies have examined early childhood risk factors for ED pathology. Given well-established links between temperament and psychopathology, examination of these factors could inform prevention efforts. The current multi-method, multi-informant prospective longitudinal study tested whether laboratory-observed and parent-reported temperament and psychiatric disorders at ages 3 and 6 (N = 609) predict body dissatisfaction at ages 12 and 15 and dimensional symptoms of EDs (anorexia nervosa [AN] and bulimia nervosa [BN]) at age 15 (n = 458) in a community sample. Results indicated that early childhood temperament (positive and negative emotionality, perceptual sensitivity, impulsivity, less shyness) and childhood psychopathology (anxiety, oppositional defiant, attention deficit/hyperactivity, and depressive disorders), predicted body dissatisfaction in adolescence. In addition, childhood perceptual sensitivity and oppositional defiant and depressive disorders predicted AN symptoms. Demographic characteristics (female sex, lower levels of fathers' education, and parental marital status) in childhood predicted body dissatisfaction and AN symptoms. No temperament or psychopathology variables predicted BN symptoms. This study is an important first step toward continuing to identify areas of focus for future research on early childhood risk factors for ED symptoms and body dissatisfaction.

Context matters: Neighborhood disadvantage is associated with increased disordered eating and earlier activation of genetic influences in girls

Emerging evidence suggests socioeconomic disadvantage may increase risk for eating disorders (EDs). However, there are very few studies on the association between disadvantage and EDs, and all have focused on individual-level risk factors (e.g., family income). Neighborhood disadvantage (i.e., elevated poverty and reduced resources in one's neighborhood) is associated with increased risk for anxiety/depression and poor physical health. To date, no studies have examined phenotypic associations between neighborhood disadvantage and disordered eating, or how any form of disadvantage may interact with genetic individual differences in risk for EDs. We examined phenotypic and etiologic associations between neighborhood disadvantage and disordered eating in 2,922 girls ages 8-17 from same-sex twin pairs recruited through the Michigan State University Twin Registry. Parents rated the twins on nine items assessing core disordered eating symptoms (e.g., weight preoccupation, binge eating), and neighborhood disadvantage was calculated from 17 indicators of contextual disadvantage (e.g., median home value, neighborhood unemployment). Puberty was measured using the Pubertal Development Scale to examine whether associations were consistent across development. At a phenotypic level, greater neighborhood disadvantage was associated with significantly greater disordered eating symptoms in girls at all stages of puberty (β = .07). Moreover, Genotype × Environment models showed that girls living in more disadvantaged neighborhoods exhibited stronger and earlier (i.e., during pre/early puberty) activation of genetic influences on disordered eating. Results highlight the critical importance of considering contextual disadvantage in research on etiology and risk for disordered eating, and the need for increased screening and treatment for EDs in disadvantaged youth. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Gonadal Hormone Influences on Sex Differences in Binge Eating Across Development

PURPOSE OF REVIEW

Binge eating is a transdiagnostic symptom that disproportionately affects females. Sexually dimorphic gonadal hormones (e.g., estradiol, testosterone) substantially impact eating behavior and may contribute to sex differences in binge eating. We examine recent evidence for the role of gonadal hormones in binge eating risk across development.

RECENT FINDINGS

Both organizational (long-lasting impact on the central nervous system (CNS)) and activational (transient influences on the CNS) hormone effects may contribute to sex differences in binge eating. Gonadal hormones also impact within-sex variability in binge eating, with higher estradiol levels in females and higher testosterone levels in males protective across development. Emerging evidence suggests that the impact of gonadal hormones may be greatest for people with other risk factors, including genetic, temperamental (e.g., high negative affect), and psychosocial (e.g., exposure to weight-based teasing) risk. Gonadal hormones contribute to sex differences and within-sex variability in binge eating across development.

The effects of puberty on associations between mood/personality factors and disordered eating symptoms in girls

OBJECTIVE

Negative and positive urgency, anxiety, and depressive symptoms are significant factors of disordered eating (DE) symptoms in early adolescence through young adulthood. However, it is unclear how puberty-a critical developmental milestone that is associated with increased risk for DE symptoms-affects the relationship between these factors and DE symptoms, given that the role of pubertal status has rarely been considered in relation to these associations. Thus, the present study examined whether puberty moderates associations between mood/personality factors and DE in pre-adolescent and adolescent girls.

METHOD

Participants included 981 girls (aged 8-16 years) from the Michigan State University Twin Registry. Mood/personality factors, pubertal status, and DE were assessed with self-report questionnaires.

RESULTS

Puberty significantly moderated associations between several factors (negative urgency, positive urgency, trait anxiety, depressive symptoms) and the cognitive symptoms of DE (e.g., shape/weight concerns, body dissatisfaction). Associations between mood/personality factors and cognitive DE were stronger in girls with more advanced pubertal status. By contrast, no significant moderation effects were detected for mood/personality-dysregulated eating (e.g., binge eating, emotional eating) associations.

DISCUSSION

Findings identify pubertal development as an important moderator of mood/personality-DE symptom associations, especially for cognitive DE symptoms that are known to predict the later onset of clinical pathology.

Gender-specific approach in psychiatric diseases: Because sex matters

In both animals and human beings, males and females differ in their genetic background and hormonally driven behaviour and show sex-related differences in brain activity and response to internal and external stimuli. Gender-specific medicine has been a neglected dimension of medicine for long time, and only in the last three decades it is receiving the due scientific and clinical attention. Research has recently begun to identify factors that could provide a neurobiological basis for gender-based differences in health and disease and to point to gonadal hormones as important determinants of male-female differences. Animal studies have been of great help in understanding factors contributing to sex-dependent differences and sex hormones action. Here we review and discuss evidence provided by clinical and animal studies in the last two decades showing gender (in humans) and sex (in animals) differences in selected psychiatric disorders, namely eating disorders (anorexia nervosa, bulimia nervosa, binge eating disorder), schizophrenia, mood disorders (anxiety, depression, obsessive-compulsive disorder) and neurodevelopmental disorders (autism spectrum disorders, attention-deficit/hyperactivity disorder).

A Narrative Review of Sex Differences in Eating Disorders: Is There a Biological Basis?

PURPOSE

Eating disorders and their core symptoms (eg, binge eating, body weight/shape concerns) disproportionately affect females, and these sex-differentiated effects become prominent during and after puberty. Although psychosocial influences such as heightened sociocultural pressures for thinness in girls and women contribute to this sex imbalance, biological factors could also play an important role.

METHODS

This narrative review summarizes evidence of biological factors underlying the sex-differentiated prevalence of eating pathology as well as within-sex variability in risk.

FINDINGS

There are sex differences in the pubertal emergence of genetic effects on eating pathology (adrenarche in males; gonadarche in females), and at least some genetic contributions to eating pathology seem to vary between the sexes. Furthermore, sex steroid hormones (eg, testosterone, estradiol, progesterone) are leading contributors to differential risk for eating pathology in males and females across the life span. Emerging data suggest that between-sex and within-sex variability in risk might occur via hormone-driven modulation (activation/deactivation) of genetic influences and neural responsiveness to food-related cues.

IMPLICATIONS

There is a biological basis to heightened risk for eating pathology in females, relative to males, as well as unique biological influences within each sex. Findings from this review highlight the importance of studying both sexes and considering sex-specific biological mechanisms that may underlie differential risk for eating pathology.

Theoretical and Methodological Considerations for Research on Eating Disorders and Gender

Gender is a relevant factor in the etiology of eating disorders (ED) as evidenced by gender-specific components of disordered eating and by the high risk of ED among transgender individuals, in addition to other factors. However, research on connections between ED and gender identity are limited. Researchers who produce explanatory models, content themselves with faulting the sociocultural ideal of slimness for women, but they fail to grasp the connection between culture, gender and the body and they fall short of integrating this perspective into existing psychological knowledge about ED. Psychological research informed by feminist theory has begun to bridge this gap, but this growing area of research needs to be further developed and should include an understanding of ED in persons with all gender identities. This article expands the discussion of gender and ED, by grounding ED in an understanding of gender itself and by discussing methodological implications of this understanding.

A 30-year longitudinal study of body weight, dieting, and eating pathology across women and men from late adolescence to later midlife

Eating disorders (EDs) are more common among younger women compared to older women and in women compared to men. As such, most ED research focuses on late adolescent and young adult females resulting in limited prospective research on gender differences in eating disorder psychopathology across the life span. The present study addresses this gap by examining gender differences in ED diagnoses, eating pathology, and the impact of putative risk factors on eating pathology in women (n = 624) and men (n = 276) over a 30-year period from late adolescence (M (SD) = 20[2] years) to later midlife (M (SD) = 50[2] years). Four assessment waves were conducted, beginning with baseline participation during college and subsequent 10-, 20-, and 30-year follow-up. Retention at 30-year follow-up was 72% (n = 440) for women and 67% (n = 181) for men. Prevalence of DSM-5 ED diagnoses decreased over the 30-year span for women and remained stable for men, with no significant gender difference in point prevalence by age 50. Drive for thinness decreased for women through age 50 and increased for men, while bulimic symptoms decreased as both genders aged. Multilevel models demonstrated that the impact of dieting as a risk factor on drive for thinness decreased prospectively as men aged and remained stable as women aged. Results imply that current risk models require refinement to account for developmental trajectories in which dramatic gender differences observed in late adolescence diminish over time. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Momentary associations between positive affect dimensions and dysregulated eating during puberty in a diverse sample of youth with overweight/obesity

OBJECTIVE

The link between dysregulated positive affect and binge-eating behavior in youth with obesity is poorly understood. In addition, it is unclear how putative associations differ across developmental periods of rapid biological and emotional change, such as puberty, and in racial and ethnic minority youth, who are more likely to be overweight but are underrepresented in the literature.

METHOD

This study used a 2-week ecological momentary assessment protocol to examine independent and interactive effects of positive affect intensity/instability, and pubertal stage on two components of binge-eating behavior, loss of control eating (LOCE), and overeating.

RESULTS

Participants were 38 youth with overweight/obesity (ages 8-14 years; 78% African American/Hispanic). Positive affect instability was calculated using probability of acute change (PAC), representing the likelihood of extreme affective changes, and mean squared successive difference (MSSD), representing the average change in affect over successive recordings. There were no main effects of positive affect intensity on LOCE or overeating, but positive affect instability was negatively associated with overeating severity using both MSSD (p = .005) and PAC metrics (p = .001). However, moderation analyses including interactions with pubertal status revealed more extreme changes in positive affect (i.e., higher PAC) were related to greater overeating (p = .001) and LOCE severity (p = .043) in mid-late pubertal youth but not in pre-early pubertal youth.

DISCUSSION

Pubertal status may influence the association between disruptions in positive affect and dysregulated eating in youth, and positive affect instability may be important to consider in order to understand the emotional correlates of binge eating in youth with overweight/obesity.

Estradiol treatment attenuates high fat diet-induced microgliosis in ovariectomized rats

Consumption of a high fat diet (HFD) increases circulating free fatty acids, which can enter the brain and promote a state of microgliosis, as defined by a change in microglia number and/or morphology. Most studies investigating diet-induced microgliosis have been conducted in male rodents despite well-documented sex differences in the neural control of food intake and neuroimmune signaling. This highlights the need to investigate how sex hormones may modulate the behavioral and cellular response to HFD consumption. Estradiol is of particular interest since it exerts a potent anorexigenic effect and has both anti-inflammatory and neuroprotective effects in the brain. As such, the aim of the current study was to investigate whether estradiol attenuates the development of HFD-induced microgliosis in female rats. Estradiol- and vehicle-treated ovariectomized rats were fed either a low-fat chow diet or a 60% HFD for 4 days, after which they were perfused and brain sections were processed via immunohistochemistry for microglia-specific Iba1 protein. Four days of HFD consumption promoted microgliosis, as measured via an increase in the number of microglia in the arcuate nucleus (ARC) of the hypothalamus and nucleus of the solitary tract (NTS), and a decrease in microglial branching in the ARC, NTS, lateral hypothalamus (LH), and ventromedial hypothalamus. Estradiol replacement attenuated the HFD-induced changes in microglia accumulation and morphology in the ARC, LH, and NTS. We conclude that estradiol has protective effects against HFD-induced microgliosis in a region-specific manner in hypothalamic and hindbrain areas implicated in the neural control of food intake.

Differences in genetic and environmental influences on body weight and shape concerns across pubertal development in females

The heritability of disordered eating increases during puberty; however, prior studies have largely examined a composite score of disordered eating, rather than specific symptoms. Body weight and shape concerns cut across all eating disorder diagnoses and are some of the strongest prospective risk factors for the development of eating disorders. Yet, little is known about potential developmental increases or decreases in genetic and environmental influences for these key symptoms. This study examined differences in genetic and environmental effects on a range of body weight and shape concerns during puberty and compared results to findings for overall levels of disordered eating symptoms. Participants were 926 same-sex female twins (ages 8-16) from the Michigan State University Twin Registry. Well-validated questionnaires were used to examine pubertal maturation, overall levels of disordered eating, and a range of cognitive body weight/shape constructs: body dissatisfaction, weight/shape concerns, and weight preoccupation. Findings for overall levels of disordered eating were very similar to those obtained in previous work, with significantly increased genetic effects in girls at more advanced pubertal development. Importantly, these same pubertal increases in genetic influences were observed for body dissatisfaction and weight/shape concerns. However, no pubertal moderation of genetic effects was observed for weight preoccupation; instead, pubertal moderation of nonshared and shared environmental effects was observed. Our findings point to differences in the extent to which genetic and environmental factors contribute to various cognitive body weight and shape symptoms during puberty.

Premenstrual symptoms as a marker of ovarian hormone sensitivity in eating disorders

OBJECTIVE

Research indicates a link between ovarian hormones and eating pathology, suggesting that some women with an eating disorder may be ovarian hormone sensitive. Using premenstrual symptoms (PMS) as an indirect measure of ovarian hormone sensitivity, we investigated the association between 11 PMS domains and four core eating disorder symptoms: body dissatisfaction, binge eating, purging, and restriction.

METHOD

Participants were young adult women (N = 455) who completed an online survey. PMS were assessed using the Daily Record of Severity of Problems and eating pathology with the Eating Pathology Symptoms Inventory. Pearson correlations were calculated between PMS domains and eating disorder symptoms followed by a stepwise regression to create a more refined model for each eating disorder symptom, including relevant covariates.

RESULTS

Significant correlations between a majority of eating disorder symptoms and PMS emerged (r's = .13-.37; p < .01). Backward regression revealed significant PMS domain predictors for each symptom. The final models captured a small-to-moderate amount of variance for each eating disorder symptom (R² = 0.06-0.25).

DISCUSSION

Women who experience physical and psychological PMS may be at risk for eating disorder symptoms; PMS could be a marker of ovarian hormone sensitivity in women at risk for an eating disorder. Future studies should address mechanisms underlying this association.

A developmental framework of binge-eating disorder based on pediatric loss of control eating

Although binge-eating disorder may manifest in childhood, a significantly larger proportion of youth report episodes involving a loss of control while eating, the hallmark feature of binge eating that predicts excess weight gain and obesity. Adults with binge-eating disorder often report that symptoms emerged during childhood or adolescence, suggesting that a developmental perspective of binge eating may be warranted. Thus, loss of control eating may be a marker of prodromal binge-eating disorder among certain susceptible youth. The present article offers a broad developmental framework of binge-eating disorder and proposes areas of future research to determine which youths with loss of control eating are at risk for persistent and exacerbated behavior that may develop into binge-eating disorder and adult obesity. To this end, this article provides an overview of loss of control eating in childhood and adolescence, including its characterization, etiology, and clinical significance, with a particular focus on associations with metabolic risk, weight gain, and obesity. A conceptual model is proposed to further elucidate the mechanisms that may play a role in determining which youths with loss of control are at greatest risk for binge-eating disorder and obesity. Ways in which treatments for adult binge-eating disorder may inform approaches to reduce loss of control eating and prevent excess weight gain in youth are discussed. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Feeding and eating disorders

Eating disorders (EDs) are a group of prevalent psychiatric illnesses with an onset in early to late adolescence-a time of significant neural development, physical and psychologic growth, and self-exploration. The etiology and neurobiology of EDs are not well understood, but EDs are recognized as brain-based illnesses with serious acute and long-term consequences if undertreated or ignored. Two EDs, anorexia nervosa (AN) and bulimia nervosa (BN), have historically been the primary EDs of focus. The DSM-5 updated diagnostic criteria for these disorders added two more: binge-eating disorder (BED) and avoidant/restrictive food intake disorder (ARFID). EDs severely impact males as well as females across the weight spectrum. Comorbidity is high; mortality rates for AN and BN are the highest in psychiatric conditions and higher than many medical conditions. Several treatment options are available to treat an ED ranging from inpatient hospitalization to outpatient services and different psychotherapy options. This chapter reviews the diagnostic criteria, clinical presentation, and treatment for these disorders. Where available, sex differences and developmental considerations will be noted. For all EDs, early recognition and swift treatment are necessary to avoid a chronic course.

Gonadal hormone contributions to individual differences in eating disorder risk

PURPOSE OF REVIEW

Females experience eating disorders at substantially higher rates than males. Although sociocultural factors have traditionally been thought to underlie this sex disparity, accumulating evidence implicates differential exposure to gonadal hormones early in life. Gonadal hormones also impact within-sex variability in disordered eating, helping to explain why not all women develop an eating disorder, and some men do. We review recent findings regarding these gonadal hormone effects and their implications for the etiology of eating disorders.

RECENT FINDINGS

Males are exposed to significantly higher testosterone levels than females perinatally, and this exposure appears to protect against later binge eating in males relative to females. Within-sex, higher estradiol levels among females and higher testosterone levels among males appear to be protective. Progesterone exhibits minimal direct phenotypic effects on disordered eating but appears to counteract the protective effects of estrogen in adult females. Importantly, gonadal hormone effects may be moderated by psychosocial factors.

SUMMARY

Evidence suggests that gonadal hormones play a critical role in the etiology of disordered eating. Overall, higher testosterone and estrogen appear to be protective across development. Additional research is needed to identify mechanisms underlying these effects and further explore interactions between hormonal and psychosocial risk.

The Role of Puberty and Ovarian Hormones in the Genetic Diathesis of Eating Disorders in Females

Puberty is a critical risk period for eating disorders (EDs). ED incidence increases across the pubertal period and becomes female predominant, and genetic influences on disordered eating significantly increase. Surges of ovarian hormones, particularly estrogen, may drive this increasing genetic effect for EDs in pubertal girls and contribute to differential phenotypic presentations beyond puberty. In this article, we explain phenotypic associations between puberty and disordered eating and present evidence showing underlying genetic and hormonal influence. Potential benefits of communicating roles of genetic influence to people with or at risk for EDs are also discussed.

Elucidating factors underlying parent-offspring similarity in eating pathology in pre- and early puberty: Exploring the possibility of passive gene-environment correlation

Familial resemblance in eating pathology is typically attributed to parents providing an environment that leads to the development of eating pathology. However, offspring raised by biological parents receive both their environment and genes from their parents, raising the possibility that genetic influences, environmental influences, and/or gene-environment interplay may account for familial resemblance. Past studies have not explored the possibility of parents' genes influencing the environment they provide (i.e., passive gene-environment correlations or "passive rGE"). If present, passive rGE is most likely to "hide" in estimates of shared environmental influence in classical twin models. The current study used a nuclear twin family design to explore the possibility of passive rGE during pre- and early puberty when past studies have demonstrated the importance of shared environmental influence. Additionally, the present study explored whether sibling-specific (i.e., influences specific to the twin generation) or family-specific (i.e., "cultural" influences within the home) environmental influences account for shared environmental influences found in past studies. Participants included preearly pubertal same-sex female twins and their biological parents (N = 547 families) from the Minnesota Twin Family Study and the Michigan State University Twin Registry. Disordered eating was assessed with self-report measures in the twins and parents. Pubertal status was determined using an established cut-off on a self-report measure. Passive rGE was not indicated in this study of pre- and early pubertal twins. Instead, sibling-specific shared environmental and nonshared environmental influences were most influential. Future research should work to identify the sibling-specific environmental influences that contribute to sibling similarity in disordered eating. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Sex Differences in Adolescent Anorexia and Bulimia Nervosa: Beyond the Signs and Symptoms

PURPOSE OF REVIEW

We review research related to sex differences in eating disorders (EDs) in adolescents. Prior work has explored clinical differences; thus, we examine literature in areas identified as playing an etiological or maintenance role in EDs including: genetics, hormones, neurocognitive inefficiencies, and reward circuitry.

RECENT FINDINGS

Sex steroids appear to a play role in the unmasking of genetic risk for development of EDs and puberty may be a heightened period of risk for females. While neurocognitive differences have been well studied in adults with ED, research with adolescents has been less conclusive. Recent work suggests that neural circuitry involved in reward and punishment may play role in development and maintenance of EDs in females. Males are underrepresented in these areas of research. Given known sex differences in healthy adolescents, it is likely there are sex differences in the putative biological etiology/maintenance of EDs. Males should be included in future research.

Prevalence of Eating Disorders Among US Children Aged 9 to 10 Years: Data From the Adolescent Brain Cognitive Development (ABCD) Study

This study extrapolates data from the Adolescent Brain Cognitive Development (ABCD) study to estimate the prevalence of eating disorders in US preadolescent children.

Sex-Gender Comparisons in Comorbidities of Children and Adolescents With High-Functioning Autism Spectrum Disorder

Over the last few years, new studies focused their attention on the gender-related features in high-functioning autism spectrum disorder (HFA), often leading to controversial results. Another interesting aspect of these subtype of patients is linked to the complexity of clinical presentation, where besides core symptoms, other co-occurrence disorders may complicate the diagnostic evaluation. Therefore, we retrospectively studied 159 HFA patients, male and female, investigating their comorbidities and to find any gender difference. For each patient, were evaluated the presence/absence, type and gender distribution of psychopathological comorbidities, according to DSM-5 diagnostic criteria. The total sample was divided in 100 male and 59 female patients, age and intelligence quotient matched. In our sample, the psychiatric comorbidities observed were Attention Deficit Hyperactivity Disorder, Anxiety Disorders, Depressive Disorders, Bipolar Disorder, Obsessive-Compulsive Disorder, and Anorexia Nervosa. No statistical significant differences were found between male and female HFA patients comorbidities except for Anorexia Nervosa. In both male and female patients, attention deficit and hyperactivity disorder and anxiety disorders were found in high percentage. In conclusion, our investigation showed that a statistical significant difference of comorbidity between male and female HFA patients was found only for AN diagnosis. However, the question about the distinction between female and male HFA patients remains quite interesting and an open area of research for future studies.

Illicit Drug Use, Cigarette Smoking, and Eating Disorder Symptoms: Associations in an Adolescent Twin Sample

OBJECTIVE

Twin studies have shown that genetic factors in part explain the established relation between alcohol use (i.e., problematic use or abuse/dependence) and eating disorder symptoms in adolescent and adult females. However, studies have yet to elucidate if there are similar shared genetic factors between other aspects of substance involvement, such as illicit drug use and repeated cigarette smoking.

METHOD

For those sex-specific phenotypic correlations above our threshold of .20, we used a behavioral genetic design to examine potential shared genetic overlap between self-reported lifetime illicit drug use and repeated cigarette smoking and the eating disorder symptoms of drive for thinness (DT), bulimia (BU), and body dissatisfaction (BD), as assessed with the Eating Disorder Inventory-II, in 16- to 17-year-old female and male twin pairs.

RESULTS

Only phenotypic correlations with illicit drug use met our threshold for twin modeling. Small to moderate genetic correlations were observed between illicit drug use and BU in both girls and boys and between illicit drug use and DT in girls.

CONCLUSIONS

Similar etiological factors are at play in the overlap between illicit drug use and certain eating disorder symptoms in girls and boys during adolescence, such that genetic factors are important for covariance. Specifically, illicit drug use was associated with bulimia nervosa symptoms in girls and boys, which parallels previous substance use research finding a genetic overlap between alcohol use and bulimia nervosa symptoms. Future research should prospectively examine developmental trajectories to further understand the etiological overlap between substance involvement and eating disorder symptoms.

Childhood body mass index and development of eating disorder traits across adolescence

OBJECTIVE

Understanding the role of premorbid body mass index (BMI) in the emergence of eating disorders may be key to identifying effective prevention strategies. We explore relations between BMI and eating disorders traits in young twins.

METHOD

The effect of BMI at age 9/12 and 15 on eating disorder traits measured using the Eating Disorders Inventory-2 (EDI) at ages 15 and 18 was examined using bivariate modelling in a longitudinal population sample of Swedish twins.

RESULTS

The correlation between BMI and EDI within individuals was stable across all ages and remained significant after adjusting for later BMI. Bivariate analysis indicated significant positive genetic correlations between BMI ages 9/12 and 15 and subsequent EDI scores. The relationship remained significant for BMI age 9/12 and EDI age 15 in the adjusted model, indicating a longitudinal association.

CONCLUSION

Our results have implications for conceptualizing the interrelation of BMI and eating disorders across childhood and adolescence.

Estrogen moderates genetic influences on binge eating during puberty: Disruption of normative processes?

Puberty is a critical period for changes in genetic effects for binge eating in girls. Previous twin studies show increases in genetic influences on binge eating from prepuberty (∼0%) to midpuberty and beyond (∼50%). However, little is known about the factors that drive these shifts in genetic effects. A small pilot study showed that pubertal activation of estrogen may contribute to increases in genetic influences, possibly via hormonally induced changes in gene expression. However, large-scale studies investigating hormone effects on genetic risk are lacking. Thus, the purpose of the present study was to examine the effects of estrogen on genetic influences for binge eating in 964 female twins (ages 8-16 years) from the Michigan State University Twin Registry. Binge eating was assessed with the Minnesota Eating Behaviors Survey, whereas afternoon saliva samples were assayed for estradiol levels using standard enzyme immunoassays. Twin moderation models showed substantial differences in genetic influences on binge eating across estradiol levels. Stronger genetic effects were observed at lower (rather than higher) estradiol levels, even when controlling for the effects of age, body mass index, the physical changes of puberty, and the onset of menses. Overall, findings suggest that comparatively lower levels of estradiol during this critical period may disrupt normative developmental processes and enhance genetic influences on binge eating. (PsycINFO Database Record

Central regulation of energy metabolism by estrogens

BACKGROUND

Estrogenic actions in the brain prevent obesity. Better understanding of the underlying mechanisms may facilitate development of new obesity therapies.

SCOPE OF REVIEW

This review focuses on the critical brain regions that mediate effects of estrogens on food intake and/or energy expenditure, the molecular signals that are involved, and the functional interactions between brain estrogens and other signals modulating metabolism. Body weight regulation by estrogens in male brains will also be discussed.

MAJOR CONCLUSIONS

17β-estradiol acts in the brain to regulate energy homeostasis in both sexes. It can inhibit feeding and stimulate brown adipose tissue thermogenesis. A better understanding of the central actions of 17β-estradiol on energy balance would provide new insight for the development of therapies against obesity in both sexes.

The significant effects of puberty on the genetic diathesis of binge eating in girls

OBJECTIVE

Recent data show significant phenotypic and genetic associations between ovarian hormones and binge eating in adulthood. Theories of hormonal risk focus on puberty and the possibility that hormone activation induces changes in genetic effects that then lead to differential risk for binge eating in postpuberty and adulthood. Although this theory is difficult to test in humans, an indirect test is to examine whether genetic influences on binge eating increase during the pubertal period in girls. Prior work has shown pubertal increases in genetic influences on overall disordered eating symptoms, but no study to date has examined binge eating. The present study was the first to examine these increases for binge eating.

METHODS

Participants included 1,568 female twins (aged 8-25 years) from the Michigan State University Twin Registry. Binge eating and pubertal development were assessed with self-report questionnaires.

RESULTS

Twin moderation models showed significant linear increases in genetic effects from prepuberty (5%) to postpuberty (42%), even after controlling for the effects of age and body mass index.

DISCUSSION

Results provide critical support for increased genetic influences on binge eating during puberty. Additional studies are needed to identify hormonal mechanisms and fully test contemporary models of ovarian hormone risk.

Expanding the developmental boundaries of etiologic effects: The role of adrenarche in genetic influences on disordered eating in males

Genetic influences on disordered eating (DE) increase across age and puberty in girls, an effect that is at least partially due to ovarian hormone activation. However, development shifts in genetic effects have not been detected in boys; genetic influences have been found to be relatively constant from prepuberty to adulthood, suggesting that gonadal hormones may be less important. One caveat is that studies have examined males ages 10 or older. Genetic effects on DE may emerge earlier in boys, such as during adrenarche, when androgens begin to increase but the physical changes of puberty are not yet observable. The current study investigated this hypothesis in 1,212 male twins (ages 6-28) from the Michigan State University Twin Registry. Results supported a potential role of adrenarche, as genetic influences on DE increased during middle childhood, prior to the external physical changes of puberty. Specifically, genetic influences on DE were negligible (0%) in twins during pre- to early adrenarche, but increased incrementally across advancing adrenarche (17% to 44%) and into early puberty (57%). Genetic effects then remained stable into midpuberty and postpuberty (58%), suggesting that nearly all of the genetic effects on DE become prominent during adrenarche in males. Findings suggest that genetic effects on DE emerge sooner in boys than the midpubertal activation that is consistently found in girls. These data highlight a potentially important role for adrenarche in the genetic diathesis for DE in males and a need to examine younger ages in studies of developmental effects. (PsycINFO Database Record

Weak associations between pubertal development and psychiatric and behavioral problems

Pubertal development has been associated with adverse outcomes throughout adolescence and adulthood. However, much of the previous literature has categorized outcome variables and pubertal timing measures for ease of mean difference or odds ratio interpretation. We use a UK-representative sample of over 5000 individuals drawn from the Twins Early Development Study to extend this literature by adopting an individual differences approach and emphasizing effect sizes. We investigate a variety of psychiatric and behavioral measures collected longitudinally at ages 11, 14 and 16, for multiple raters and for males and females separately. In addition, we use two measures of pubertal development: the Pubertal Development Scale at each age, as well as the age of menarche for girls. We found that pubertal development, however assessed, was linearly associated with a range of psychiatric and behavioral outcomes; however, the effect sizes of these associations were modest for both males and females with most correlations between -0.10 and 0.10. Our systematic analysis of associations between pubertal development, and psychiatric and behavioral problems is the most comprehensive to date. The results showing linearity of the effects of pubertal development support an individual differences approach, treating both pubertal development and associated outcomes as continuous rather than categorical variables. We conclude that pubertal development explains little variance in psychiatric and behavioral outcomes (<1% on average). The small effect sizes indicate that the associations are weak and should not warrant major concern at least in non-clinical populations.

Sex Differences in Binge Eating: Gonadal Hormone Effects Across Development

Eating disorders are highly sexually differentiated disorders that exhibit a female predominance in risk. Most theories focus on psychosocial explanations to the exclusion of biological/genetic influences. The purpose of this descriptive review is to evaluate evidence from animal and human studies in support of gonadal hormone effects on sex differences in binge eating. Although research is in its nascent stages, findings suggest that increased prenatal testosterone exposure in males appears to protect against binge eating. Although pubertal testosterone may exert additional protective effects, the prenatal period is likely critical for the decreased risk observed in males. By contrast, studies indicate that, in females, it is the lack of prenatal testosterone coupled with the organizational effects of pubertal ovarian hormones that may lead to increased binge eating. Finally, twin data suggest that changes in genetic risk may underlie these hormone influences on sex differences across development.

Differential Effects of Estrogen and Progesterone on Genetic and Environmental Risk for Emotional Eating in Women

Recent data show shifts in genetic and environmental influences on emotional eating across the menstrual cycle, with significant shared environmental influences during pre-ovulation, and primarily genetic effects during post-ovulation. Factors driving differential effects are unknown, although increased estradiol during pre-ovulation and increased progesterone during post-ovulation are thought to play a role. We indirectly investigated this possibility by examining whether overall levels of estradiol and progesterone differentially impact genetic and environmental risk for emotional eating in adult female twins (N = 571) drawn from the MSU Twin Registry. Emotional eating, estradiol levels, and progesterone levels were assessed daily and then averaged to create aggregate measures for analysis. As predicted, shared environmental influences were significantly greater in twins with high estradiol levels, whereas additive genetic effects increased substantially across low versus high progesterone groups. Results highlight significant and differential effects of ovarian hormones on etiologic risk for emotional eating in adulthood.

Association Between Pubertal Onset and Symptoms of ADHD in Female University Students

OBJECTIVE

This exploratory study investigated how the timing of female pubertal maturation was associated with the symptoms of ADHD in a non-clinical female undergraduate sample (N = 253).

METHOD

Participants (Mage = 20.2 ± 1.7 years) completed a set of self-report rating scales examining pubertal onset and ADHD symptoms and related deficits.

RESULTS

Logistic regression analysis indicated that early puberty was associated with elevation in symptoms, including difficulties in attention (odds ratio [OR] = 1.270, p = .019), emotion regulation (OR = 1.070, p = .038), and more risky behavior (OR = 1.035, p = .045). That is, increased symptom endorsement was shown to significantly help classify those who reported having an earlier pubertal onset relative to their peers.

CONCLUSION

Findings highlight the potential role of sex hormones during puberty in explaining the gender differences in prevalence rates of ADHD and symptom profiles.

Towards a science of eating disorders: Replacing myths with realities: The fourth Birgit Olsson lecture

BACKGROUND

For too long we have been "stuck" in old perspectives that have hampered the advance of knowledge. In part, this is related to the challenges that people have in unlearning misinformation.

AIM

To address the need for an upgrade in the eating disorders field.

METHOD

To assist with replacing outdated and inaccurate ideas with new data, this lecture reviewed novel approaches to eating disorders that engage scientists and clinicians from diverse fields to approach questions about aetiology and treatment of eating disorders through new lenses. This forward-looking lecture outlined critical questions that need to be addressed to move the field forward and strategies for engaging scientists from different fields.

RESULTS

Leading-edge findings on genetics, intestinal microbiota, and neuroscience are reviewed.

CONCLUSIONS

This review encourages the integration of new evidence-based knowledge to form the backbone of our understanding of and approach to eating disorders.