Jennifer D. Slane

The Effects of Puberty on Genetic Risk for Disordered Eating: Evidence for a Sex Difference

BACKGROUND Differences in genetic influences on disordered eating are present across puberty in girls. Heritability is 0% before puberty, but over 50% during and after puberty. Emerging data suggest that these developmental differences may be due to pubertal increases in ovarian hormones. However, a critical piece of evidence is lacking, namely, knowledge of genetic influences on disordered eating across puberty in boys. Boys do not experience increases in ovarian hormones during puberty. Thus, if pubertal increases in genetic effects are present in boys, then factors in addition to ovarian hormones may drive increases in heritability in girls. The current study was the first to examine this possibility in a sample of 1006 male and female twins from the Michigan State University Twin Registry. METHOD Disordered eating was assessed with the Minnesota Eating Behavior Survey. Pubertal development was assessed with the Pubertal Development Scale. RESULTS No significant differences in genetic influences on disordered eating were observed in males across any developmental stage. Heritability was 51% in boys during pre-puberty, puberty and young adulthood. By contrast, in girls, genetic factors accounted for 0% of the variance in pre-puberty, but 51% of the variance during puberty and beyond. Sex differences in genetic effects were only significant during pre-puberty, as the best-fitting models constrained heritability to be equal across all males, pubertal females and young adult females. CONCLUSIONS The results highlight sex-specific effects of puberty on genetic risk for disordered eating and provide indirect evidence of a role for ovarian hormones and/or other female-specific factors.

Bupropion and cognitive behavioral therapy for weight-concerned women smokers.

BACKGROUND We previously documented that cognitive behavioral therapy for smoking-related weight concerns (CONCERNS) improves cessation rates. However, the efficacy of combining CONCERNS with cessation medication is unknown. We sought to determine if the combination of CONCERNS and bupropion therapy would enhance abstinence for weight-concerned women smokers. METHODS In a randomized, double-blind, placebo-controlled trial, weight-concerned women (n = 349; 86% white) received smoking cessation counseling and were randomized to 1 of 2 adjunctive counseling components: CONCERNS or STANDARD (standard cessation treatment with added discussion of smoking topics but no specific weight focus), and 1 of 2 medication conditions: bupropion hydrochloride sustained release (B) or placebo (P) for 6 months. Rates and duration of biochemically verified prolonged abstinence were the primary outcomes. Point-prevalent abstinence, postcessation weight gain, and changes in nicotine withdrawal, depressive symptoms, and weight concerns were evaluated. RESULTS Women in the CONCERNS + B group had higher rates of abstinence (34.0%) and longer time to relapse than did those in the STANDARD + B (21%; P = .05) or CONCERNS + P (11.5%; P = .005) groups at 6 months, although rates of prolonged abstinence in the CONCERNS + B and STANDARD + B groups did not differ significantly at 12 months. Abstinence rates and duration did not differ in the STANDARD + B group (21% and 19%) compared with the STANDARD + P group (10% and 7%) at 6 and 12 months, respectively. There were no differences among abstinent women in postcessation weight gain or weight concerns, although STANDARD + B produced greater decreases in nicotine withdrawal and depressive symptoms than did STANDARD + P. CONCLUSIONS Weight-concerned women smokers receiving the combination of CONCERNS + B were most likely to sustain abstinence. This effect was not related to differences in postcessation weight gain or changes in weight concerns. Trial Registration clinicaltrials.gov Identifier: NCT00006170.

Negative affect as a mediator of the relationship between weight-based teasing and binge eating in adolescent girls.

Previous research has established a link between weight-based teasing and binge eating, though the precise mechanisms that drive this relationship remain unknown. This study examined negative affect as a mediator of the relationship between weight-based teasing and binge eating. Participants included 265 adolescent female twins (aged 10-15 years). Self-report measures assessed binge eating, weight-based teasing, and negative affect. Mediation was tested within hierarchical linear models to control for the non-independence of the twin data. Significant positive associations were observed between binge eating, teasing, and negative affect. In the regression analyses, negative affect partially mediated associations between weight-based teasing and binge eating. Results suggest that increases in negative affect are one way in which weight-based teasing leads to binge eating in girls. Future studies should examine additional mediators and assess possible clinical applications of these findings.

Predictors of alcohol problems in college women: The role of depressive symptoms, disordered eating, and family history of alcoholism

Disordered eating and depressive symptoms are established correlates of alcohol use in college women. Family history of alcoholism (FHA) is also related to problematic alcohol use, but there have been limited studies of how it relates to other established cofactors in women. Predictive associations between disordered eating (i.e., overall levels as well as binge eating), depressive symptoms, and alcohol problems were examined in a sample of 295 female twins. The direct and moderating effects of FHA on the relationships between alcohol problems, disordered eating, and depressive symptoms were investigated. Using hierarchical linear modeling depressive symptoms, but not disordered eating or FHA, significantly predicted alcohol problems. However, there was a significant interaction between disordered eating and FHA; disordered eating was associated with alcohol problems in those with a positive FHA. The implications for high-risk subgroups of college women are discussed.

Genetic and environmental influences on sleep problems: a study of preadolescent and adolescent twins.

BACKGROUND/AIM The aim of this study was to examine the extent to which additive genetic, shared environmental and non-shared environmental factors contribute to adolescent and preadolescent sleep problems. METHODS The sample consisted of a cohort of 270 monozygotic and 246 dizygotic twins from a university-based twin registry. RESULTS Results demonstrated that genetic and environmental influences each appear to be important to adolescent sleep problems. CONCLUSIONS While the magnitude of genetic influence on sleep problems was consistent with findings from the adult literature, it was smaller than in studies with younger children, suggesting genetic effects may be less influential in adolescence and adulthood.

Sleep Problems and Temperament in Adolescents

The aim of this study was to determine the association between temperament and sleep in adolescents. Participants included 516 adolescents and their mothers drawn from the community. Findings indicated that as with younger children, sleep and dimensions of temperament (sociability, impulsivity and negative affect) are related in adolescents.

Developmental trajectories of disordered eating from early adolescence to young adulthood: a longitudinal study.

OBJECTIVE Research examining changes in eating disorder symptoms across adolescence suggests an increase in disordered eating from early to late adolescence. However, relevant studies have largely been cross-sectional in nature and most have not examined the changes in the attitudinal symptoms of eating disorders (e.g., weight concerns). This longitudinal study aimed to address gaps in the available data by examining the developmental trajectories of disordered eating in females from preadolescence into young adulthood. METHOD Participants were 745 same-sex female twins from the Minnesota Twin Family Study. Disordered eating was assessed using the Total Score, Body Dissatisfaction subscale, Weight Preoccupation subscale, and a combined Binge Eating and Compensatory Behavior subscale from the Minnesota Eating Behavior Survey assessed at the ages of 11, 14, 18, 21, and 25. Several latent growth models were fit to the data to identify the trajectory that most accurately captures the changes in disordered eating symptoms from 11 to 25 years. RESULTS The best-fitting models for overall levels of disordered eating, body dissatisfaction, and weight preoccupation showed an increase in from 11 through 25 years. In contrast, bulimic behaviors increased to age of 18 and then stabilized to age of 25. DISCUSSION The findings expanded upon extant research by investigating longitudinal, symptom specific, within-person changes and showing an increase in cognitive symptoms into young adulthood and the stability of disordered eating behaviors past late adolescence.

Genetic and environmental influences on disordered eating and depressive symptoms

OBJECTIVE Research suggests that shared genetic factors underlie relationships between eating disorder and depression diagnoses, but no studies to date have examined these associations using dimensional symptom measures. This study examined whether genetic associations observed between eating disorder and depression diagnoses extend to continuous measures of these phenotypes. METHOD The sample consisted of 292 young adult female twins from the Michigan State University Twin Registry. Disordered eating was measured using the Minnesota Eating Behavior Survey. Depressive symptoms were assessed using the Beck Depression Inventory. RESULTS Univariate twin models indicated that genetic factors accounted for 55% to 60% of the variance in disordered eating and depressive symptoms, with the remaining variance accounted for by nonshared environmental effects. Bivariate models indicated that genetic factors primarily accounted for associations between disordered eating and depressive symptoms (r(a) = .70). DISCUSSION Phenotypic associations between disordered eating and depressive symptoms appear to be due to common genetic factors.

Interpersonal dysfunction and affect-regulation difficulties in disordered eating among men and women.

Although several studies suggest that negative affect and interpersonal problems serve as important contributors for eating-related problems, much of this research has been conducted among women and less is known about their roles in precipitating and maintaining eating problems among men. Previous studies with undergraduate men suggest that difficulties in emotion regulation are associated with disordered eating even after controlling for differences in body mass index (BMI) and negative affect. The present study sought to replicate these findings and extend them to assess any unique variance explained by problems in interpersonal functioning among both men and women. Participants were men (n=213) and women (n=521) undergraduates at a large Midwestern university who completed a demographic information form, the Eating Disorder Examination-Questionnaire (EDE-Q), the Difficulties in Emotion Regulation Scale (DERS), the Positive and Negative Affect Schedule, and the Inventory of Interpersonal Problems-Short Circumplex Form (IIP-SC). A series of hierarchical regression analyses indicated that DERS and IIP-SC significantly predicted EDE-Q global scores after controlling for variability in BMI and negative affect and that the results were similar for men and women. Our findings offer preliminary support for models that highlight emotional vulnerability and interpersonal problems for disordered eating for young adult men. Future research extending these findings among treatment-seeking samples and employing multi-method assessment would serve to further clarify the tenability of these theoretical models for both men and women.

ETIOLOGIC RELATIONSHIPS BETWEEN ANXIETY AND DIMENSIONS OF MALADAPTIVE PERFECTIONISMIN YOUNG ADULT FEMALE TWINS

Theory and research suggest that maladaptive perfectionism, specifically, concerns about mistakes (CM) and doubts about actions (DA), may be important etiologic and maintenance mechanisms for anxiety and its disorders. However, no studies speaking directly to the origins of the relationship, i.e. what etiologic factors underlie the phenotypic association between anxiety and maladaptive perfectionism, exist. The current study aimed to address this gap in the literature by exploring genetic and environmental relationships between anxiety symptoms and maladaptive perfectionism.